Curriculum Materials- Geometry Envision Math
Course Overview
The content of this course is designed to meet the needs of students who may have struggled with topics in Algebra 1, and is designed to allow time to review algebraic concepts as needed. During high school, students begin to formalize their geometry experiences from elementary and middle school, using more precise definitions and developing careful proofs. The concepts of congruence, similarity, and symmetry can be understood from the perspective of geometric transformation. Geometry topics will include Congruence, Similarity, Right Triangles and Trigonometry, Circles, Geometric Measurement and Dimension, and Modeling with Geometry. The curriculum will continue with developing the understanding of the major concepts of Euclidean geometry and students will be expected to justify all work using the definitions, postulates and theorems from the body of study.
Topic 1: Foundations of Geometry
1.1-The sum of lengths of all sections of a segment is smaller than the length of the segment; the sum of th emeasures of two smaller angles that form a larger angle is the measure of the larger angle.
1.2* - A construction is a geometric figure produced using only a straightedge and a compass. Constructions are useful tools in geometry.
1.3 - The midpoint formula is used to find the midpoint of a segment on the coordinate plane and the Distance Formula is used to find the length. The Midpoint Formula can be adapted to partition a segment into two segments with any ratio of lengths.
1.4 - Inductive reasoning can be used to identify patterns, provide evidence for or disprove conjectures, and make predictions.
1.5 - In mathematics, conditional statements are expressed as if-then statements consisting of a hypothesis and a conclusion. Conditional statements can be evaluated using truth tables.
1.6 - Deductive reasonsing is the process of using given statements or facts to logically reach a valid conclusion
1.7 - Justify statements of a proof with definitions, postulates, theorems, and properties
1.8* - In indirect reasoning, you assume that the disired conclusion is fale, which leads to a contradiction, allowing you to conclude that what you want to prove must be true.
What are some of the fundamentals of geometry?
How are symbols and vocabulary used to translate between verbal ideas and the language of geometry?
How do we use the language of geometry to express mathematical ideas and situations?
How and why do definitions, properties, and theorems form the structural basis for geometry?
Students will:
Understand why geometry requires the use of undefined terms and the acceptance of un-provable postulates.
Know the basic the basic postulates of geometry.
Know how the relationships among points, lines, segments, and rays change when they are not coplanar.
Know the difference between hypothesis and conclusion.
Know why deductive reasoning leads to definitive conclusion.
Identify the relationships that exist within any set of points.
Distinguish between postulates and conjectures.
Distinguish between congruence and equality.
Use symbolic form to represent conditional statements.
To write converses, inverses, and contra-positives of given conditional statements.
Evaluate the truthfulness of conditionals and their variants.
Write definitions as bi-conditionals.
Topic 2: Parallel and Perpendicular Lines
2.1 -When parallel lines are cut by a transversal, the special angle pairs that are formed are congruent, supplementary, or both.
2.2 - Pairs of congruent or supplementary angles formed when two lines are cut by a transversal can be used to prove parallel lines.
2.3 - The sum of the interior angles of a triangle is 180 degrees, and the measure of an exterior angle of a triangle is equal to the sum of the measures of the remote interior angles.
2.4 - Two parallel lines have equal slopes. The product of the sloes of perpendicular lines is -1.
What properties are specific to parallel lines and perpendicular lines?
Students will:
Know why the parallel postulate forms the basis of much of plane geometry.
Know planning a proof requires an understanding of what is known and what must be justified.
Know theorems are true only if they can be proved.
Know how interior and exterior angles are related.
Show that lines are parallel from angle relationships.
Identify the angles formed by two lines and a transversal.
Graph lines from their equations.
Write equations of lines from their graphs.
Determine whether lines are parallel or perpendicular from their equations.
Use algebraic details of lines in the coordinate plane to determine the properties of polygons.
Topic 3: Transformations
3.1 - Reflections are rigid motions across a line of reflection.
3.2 - A translation is a rigid motion that moves all points of the preimage the same distance in the same direction. A translation is the composition of two reflections.
3.3 - Rotation is a rigid motion described by its center of rotation and angle of rotation. Any rotation can be described by two reflections whose lines of reflection meet at the center of rtation at half the angle of rotation.
3.4 - Any composition of rigid motions can be represented by a combination of at least two of the following: a translation, reflection, rotation, or glide reflection.
3.5 - A figure that can be mapped onto itself using rigid motions is symmetric. Rotational symmetry uses rotation to mapa figure onto itself, and reflectional symmetry uses reflection to mpa a figure onto itself.
What are the properties of the four types of rigid motion?
Students will:
Find a reflected image and write a rule for a reflection.
Define reflection as a transformation across a line of reflection with given properties and perform reflections on and off a coordinate grid.
Translate a figure and write a rule for a translation.
Find the image of a figure after a composition of rigid motions.
Prove that a translation is a composition of two reflections.
Rotate a figure and write a rule for a rotation.
Prove that a rotation can be written as the composition of two reflections.
Specify a sequence of transformations that will carry a given figure onto another.
Use geometric descriptions of rigid motions to transform figures.
Describe the rotations and/or reflections that carry a polygon onto itself.
Predict the effect of a given rigid motion on a figure.
Identify types of symmetry in a figure.
Topic 4: Triangle Congruence
4.1 - Figures that have the same size and shape are congruent. If a rigid motion or composition of rigid motions can map one figure onto another, then the figures are congruent.
4.2 - An isosceles triangle has congruent base angles and legs. The angle bisector of the vertex angle of an isosceles triangle is also the perpendicular bisector of the base. An equilateral triangle is also equiangular.
4.3 - Prove triangle congruence by SSS & SAS criteria and use triangle congruence to solve problems. Understand that corresponding parts of congruent triangles are congruent and use CPCTC.
4.4 - Prove triangle congruence by ASA & AAS criteria and use triangle congruence to solve problems.Understand that corresponding parts of congruent triangles are congruent and use CPCTC.
4.5 - Prove the Hypotenuse-Leg Theorem. Use congruence criteria for triangles to solve problems and to prove relationships in geometric figures.
4.6 - Apply congruence criteria to increasingly intricate problems involving overlapping triangles and multiple triangles. Prove triangles are congruent by identifying corresponding parts and applying the correct theorems.
Why is the triangle a significant plane figure?
How are the properties and characteristics of triangles used in applications?
Students will:
Know what minimum information is necessary for establishing the congruence of two triangles
Know how to recognize corresponding congruent parts regardless of the orientation of the triangles.
Know the four congruency principles for general (non-right) triangles.
Know the congruency principle that applies to right triangles.
Know why CPCTC can be invoked only after the congruency of triangles has been established.
Identify and name congruent parts of triangles
Use the congruency of corresponding parts to establish the congruency of triangles.
Recognize when triangles are congruent on the basis of SSS, SAS, ASA, AAS, and HL.
Determine when there is enough information to prove two triangles are congruent.
Reason through the steps of a formalized geometric proof.
Show why SSA is not a useful congruency principle for general triangles.
Topic 5: Relationships in Triangles
5.1 - The perpendicular bisector of a segment contains all the points that are equidistant from the endpoints of the segment, and an angle bisector contains all the points that are equidistant from the sides of the angle.
5.2 - The perpendicular bisectors of the sides of a triangle are concurrent at its circumcenter. The angle bisectors of a triangle are concurrent at its incenter.
5.3 - The medians of a triangle are concurrent at its centroid. The lines containing the altitudes of a triangle are concurrent at its orthocenter.
5.4 -The lengths of the sides of a triangle are related to the measures of the angles in the triangle. The sum of the lengths of two sides of a triangle is greater than the length of the third side.
5.5 - When two triangles have two pairs of congruent sides, the longer third side is opposite the larger included angle, and the shorter third side is opposite the smaller included angle.
Triangles have important characteristics and properties.
How are the properties and characteristics of triangles used in applications?
What properties are common to all triangles?
Students will:
Know that triangles have special segments within them that have particular properties.
Know the distance from a point to a line is measured along the shortest segment connecting the point to the line, and so is measured perpendicular to the line.
Know Points of concurrency for special segments may be inside, on, or outside the triangle.
Know the Triangle Inequality governs the lengths of the sides of a triangle as well as utilize the Hinge Theorem.
Identify and construct the altitudes and medians of a triangle.
Identify and construct the perpendicular and angle bisectors of a triangle.
Locate the points of concurrency for each of the special segments of a triangle.
Construct inscribed and circumscribed circles for a given triangle.
Topic 6: Quadrilaterals
6.1 - The sum of the exterior angles of a polygon is 360°, regardless of the number of sides. The sum of the interior angles of a polygon is 180° • (n – 2), where n is the number of sides.
6.2 - Diagonals of a kite are perpendicular, and one diagonal bisects the other. In isosceles trapezoids, diagonals are congruent. The length of the midsegment of a trapezoid is half the sum of the lengths of the bases.
6.3 - In a parallelogram, consecutive angles are supplementary, opposite angles are congruent, opposite sides are congruent, and the diagonals bisect each other.
6.4 - A quadrilateral with two pairs of congruent opposite sides, or one pair of congruent parallel sides, or diagonals bisecting each other is a parallelogram. A quadrilateral with an angle supplementary to both of its consecutive angles, or two pairs of opposite congruent angles is a parallelogram.
6.5 - The diagonals of a rhombus are perpendicular, bisect each other, and bisect opposite angles. They form four congruent triangles. In a rectangle, the diagonals are congruent. Squares have properties of rhombuses and rectangles.
6.6 - A parallelogram with perpendicular diagonals or diagonals that bisect angles is a rhombus. A parallelogram with congruent diagonals is a rectangle. A parallelogram with perpendicular congruent diagonals or with congruent diagonals and a diagonal that bisects angles is a square.
What are the unique properties and characteristics associated with individual geometric figures?
What are the properties and theorems that connect two or more geometric figures (e.g. congruence, similarity, etc)?
How can we use the properties and characteristics of figures to do real-world problems?
Students will:
Know the major classifications of quadrilaterals, especially as they derive from the existence of parallel sides.
Know how quadrilaterals may be classified by symmetries.
Know the special properties of parallelograms, and the specific parallelograms that result from imposing restrictions on the general case.
Know how the major postulates and theorems that apply to triangles can be extended to the study and analysis of quadrilaterals
Classify quadrilaterals by appearance and by their individual properties.
Distinguish among the various kinds of parallelograms
Distinguish between trapezoids and parallelograms
Show that certain features of a quadrilateral cause it to be a parallelogram
Identify specific quadrilaterals on the basis of their individual features
Topic 7: Similarity
7-1- A dilation is a transformation that preserves angle measure but not length. The dilation of a figure is determined by the scale factor and center of dilation. Every distance from the center of dilation and every side length in a preimage are multiplied by the scale factor to find the corresponding distance and side length in the image.
7-2- A similarity transformation is a dilation combined with one or more rigid motions. In order for two figures to be similar, there must be a similarity transformation that maps one figure to the other. All circles are similar.
7-3- Two triangles are similar if a composition of rigid motions and dilation will map one triangle onto the other. Two pairs of congruent angles, or three pairs of sides with lengths that are in the same proportion, or two pairs of sides having congruent included angles with lengths that are in the same proportion, are sufficient to show that two triangles are similar.
7-4- The length of the altitude to the hypotenuse of a right triangle is the geometric mean of the lengths of the two segments into which the altitude divides the hypotenuse. The length of a leg of a right triangle is the geometric mean of the length of the hypotenuse and the segment of the hypotenuse adjacent to the leg.
7-5- A segment parallel to one side of a triangle divides the triangle into two similar triangles. If that segment connects the midpoints of two sides, the smaller triangle is in proportion 1 : 2 with the larger triangle. A segment that bisects an angle of a triangle divides the opposite side of the triangle into segments that are proportional to the adjacent sides.
Why is it essential to understand the interconnectedness of geometric properties, similarity, ratios, proportions, and transformations to effectively model and solve problems across mathematics and in real-world scenarios?
Students will:
Identify and describe similarity as a characteristic of both two-dimensional (plane) and three-dimensional (solid) figures.
Apply different types of transformations (e.g., translations, rotations, reflections, dilations) to plane figures.
Analyze and explain the properties and theorems that establish relationships between two or more geometric figures, including congruence and similarity.
Articulate and demonstrate the connection between similarity of figures and the concepts of ratios and proportions.
Solve real-world problems by applying the principles and knowledge of similar figures.
Compare and contrast the relationships between algebraic representations and geometric transformations.
Topic 8: Right Triangles and Trigonometry
The Pythagorean Theorem can be understood through the relationships among the similar triangles formed by the altitude to the hypotenuse. The length of the hypotenuse of a 45-45-90 triangle is rt(2) times the leg length. The length of the hypotenuse of a 30-60-90 right triangle is twice the length of the shorter leg, and the length of the longer leg is rt(3) times the length of the shorter leg.
8.2 - For any two right triangles with a given acute angle, the ratios of any two corresponding side lengths are equal. The ratio of the opposite side to the ypotenuse is the sine ratio, the ratio of the ajdacent side to the hypotenuse is the cosine ratio, and the ratio of the opposite side to the adjacent side is the tangent ratio.
8.5 - The ratios of the corresponding sides of right triangles are constant for right triangles with given base angles and are related to the base angles. These relationships can be used to solve problems for which side lengths, angle measures, or areas of triangles are desired.
How are the Pythagorean Theorem and trigonometry useful?
Students will:
Prove the Pythagorean Theorem using similar right triangles.
Understand and apply the relationships between side lengths in 45°-45°-90° and 30°-60°-90° triangles.
Define and calculate sine, cosine, and tangent ratios.
Use trigonometric ratios to solve problems.
Understand why the Law of Sines applies to any triangle.
Use the Law of Sines to solve problems.
Develop an understanding of the Law of Cosines.
Use the Law of Cosines to solve problems.
Topic 9: Coordinate Geometry
9.1 - Algebra is used to determine properties of geometric figures drawn on the coordinate plane. Slopes can be used to determine whether segments are parallel or perpendicular, the distance formula can be used to find length of segments, and the Midpoint Formula can be used to bisect segments.
9.2 - Proofs using coordinate geometry require planning by determining the properties to be shown with algebra, drawing a labeled diagram on the coordinate plane and calculating the values needed to show the desired relationships.
9.3 - The equation of a circle in the coordinate plane is given by (x-h)^2-(y-k)^2=r^2, where (h,k) is the center of the circle and r is the radius.
How can geometric relationships be proven by applying algebraic properties to geometric figures represented in the coordinate plane?
Students will:
Use coordinate geometry to classify triangles and quadrilaterals on the coordinate plane.
Solve problems involving triangles and polygons on the coordinate plane.
Plan a method of proof using coordinate geometry.
Prove theorems using algebra and the coordinate plane.
Write the equation for a circle given the graph of the circle or given the center and radius of the circle.
Graph a circle from its equation.
Explain the relationship between a focus and directrix and the corresponding parabola.
Write equations for parabolas given the focus and directrix.
Topic 10: Circles
10.1 - Arcs are classified as minor arcs or major arcs depending on whether they are small or larger than a semicircle. The length of an arc is a part of the circumference that is proportional to the corresponding central angle. The area o f a sector of a circle is part of the area of the circle that is proportional to the central angle. The area of a segment of a circle is the area of the ocrrespnding sector minus the area of the corresponding triangle.
10.2 - A line that is tangnet to a circle intersects the circle at exactly one point and is perpendicular to the radius to that point. If two segments are tangent ot the same circle and have a common enpoint exterior to the cricle, the semgents are congruent.
10.3 - In a circle or congruent circles, two chords are congruent if the corresponding central angles are congruent or if the chords intercept congruent arcs. A diameter that bisects a chors is perpendicular to the chord.
10.4 - In a circle, the measure of an inscribed angle is one-half of the measure of its intercepted arc. In a circle, the measure of an angle formed by a chord and tangent ot the circle is one-half of the measure of its intercepted arc.
10.5 - When two secants intersect inside a circle, the measure of the angle formed is half the sum of the intercepted arcs. When secants or tangents intersect outside a cricle, the measure of the angle formed is half the difference of the intercepted arcs. When secants or tangents intersect inside or outside a circle, the products of the distances from the point of intersection to the points on a circle is the same for both lines.
How can we use the properties of arcs, tangents, chords, inscribed angles, and secants to analyze and solve problems involving circles?
Students will:
Calculate the length of an arc when the central angle is given in degrees or radians.
Calculate the area of sectors and segments of circles.
Identify lines that are tangent to a circle using angle measures and segment lengths.
Solve problems involving tangent lines.
Prove and apply relationships among chords, arcs, and central angles.
Find lengths of chords given the distance from the center of the circle, and use this information to solve problems.
Identify and apply relationships among the measures of inscribed angles, arcs, and central angles.
Identify and apply the relationships between an angle formed by a chord and a tangent to its intercepted arc.
Recognize and apply angle relationships formed by secants and tangents intersecting inside and outside a circle.
Recognize and apply segment length relationships formed by secants and tangents intersecting inside and outside a circle.