Geometry
In Fourth Grade, students learn how to Draw and Identify Lines and Angles, and Classify Shapes by Properties of their Lines and Angles. They also learn about Lines of Symmetry.Have your child check out the reference sheets and videos belowto help them learn about Geometry!
Students begin Geometry by learning some important vocabulary.
Once they are comfortable with their geometric vocabulary, they learn how to identify angles, and parallel, perpendicular, & intersecting lines within two-dimensional figures.
Students begin Geometry by learning some important vocabulary.
Once they are comfortable with their geometric vocabulary, they learn how to identify angles, and parallel, perpendicular, & intersecting lines within two-dimensional figures.
Types of Lines:
Types of Lines:
A LINE goes on and on in both directions forever and ever. A line cannot be measured.A LINE SEGMENT is a line that has two endpoints. A line segment can be measured.A RAY has one endpoint and goes on and on in one direction forever and ever. A ray cannot be measured.
Two lines intersect (meet) at a POINT. PARALLEL LINES are two lines that never intersect. They are the same distance apart in all areas.INTERSECTING LINES are two lines that meet at a point.PERPENDICULAR LINES are intersecting lines that form right angles.
Types of Angles:
Types of Angles:
An ANGLE is created when two rays meet at a point.ACUTE ANGLES are less than 90 degrees. OBTUSE ANGLES are angles that are greater than 90 degrees. RIGHT ANGLES are angles that are equal to 90 degrees.
Polygons:
Polygons:
POLYGONS are closed, plane figures with 3 or more sides.Students are responsible for identifying the following polygons:TRIangles have 3 sides and 3 angles.QUADrilaterals have 4 sides and 4 angles.PENTagons have 5 sides and 5 angles.HEXagons have 6 sides and 6 angles.OCTagons have 8 sides and 8 angles.
Triangles:
Triangles:
TRIANGLES are closed, plane figures with 3 sides, so they are included in the polygon category. Students are responsible for identifying RIGHT TRIANGLES, which have one right angle and two acute angles.
Quadrilaterials:
Quadrilaterials:
QUADRILATERALS are closed, plane figures with 4 sides. Quadrilaterals are also polygons. PARALLELOGRAMS are quadrilaterals with two pair of parallel lines.Some Quadrilaterals that are also Parallelograms are:SQUARES which have 4 congruent (equal) sides and 4 right (90 degree) angles. Opposite sides are parallel.RECTANGLES which have 4 sides and 4 right angles. Opposite sides are parallel and congruent.RHOMBUSES which are parallelograms with 4 congruent sides.Some Quadrilaterals that are NOT Parallelograms are:TRAPEZOIDS which are quadrilaterals made with one pair of parallel lines.ISOSCELES TRAPEZOIDS which are trapezoids with two congruent sides.
Symmetry:
Symmetry:
Students learn that a LINE OF SYMMETRY is a line drawn within a shape that creates two equal pieces, which are a mirror image of each other. Students then learn to identify these lines within two-dimensional figures.For example, a square has 4 lines of symmetry, and a rectangle has 2 lines of symmetry.
