Chapter 10: Two-Dimensional Figures

In Chapter 10 students will:

• draw and identify lines and angles
• classify shapes by properties of their lines and angles
• generate and analyze patterns

Chapter 10 videos:

Lesson 10.1 Lines, Rays, and Angles (CC.4.G.1)*

Lesson 10.2 Classify Triangles (CC.4.G.2)*

Lesson 10.3 Parallel and Perpendicular Lines (CC.4.G.1)*

Lesson 10.4 Classify Quadrilaterals (CC.4.G.2)*

Lesson 10.5 Line Symmetry (CC.4.G.3)*

Lesson 10.6 Find and Draw Lines of Symmetry (CC.4.G.3)^

Lesson 10.7 Problem Solving-Shape Patterns (CC.4.OA.5)^

Vocabulary:

• line – a straight path of points that continues without end in both directions
• ray - a part of a line, with one endpoint, that is straight and continues in one direction
• acute angle – an angle that has a measure less than a right angle
• obtuse angle – an angle that has a measure greater than a right angle
• right angle – an angle that forms a square corner and has a measure of 90 degrees
• straight angle - an angle in which two rays point in the opposite directions so that they form a line
• line of symmetry - an imaginary line that divides a shape into two congruent parts

line symmetry - what a shape has if it can be folded along a line so that its two parts match exactly

Chapter 10 Standards: Geometry (4.G)

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Draw and identify lines and angles, and classify shapes by properties of their lines and angles. (CC.4.G)

1. Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures. (CC.4.G.1)

2. Classify two-dimensional figures based on the presence or absence of parallel or perpendicular lines, or the presence or absence of angles of a specified size. Recognize right triangles as a category, and identify right triangles. (CC.4.G.2)

3. Recognize a line of symmetry for a two-dimensional figure as a line across the figure such that the figure can be folded along the line into matching parts. Identify line-symmetric figures and draw lines of symmetry. (CC.4.G.3)

Operations and Algebraic Thinking (4.OA)

Generate and analyze patterns.

5. Generate a number or shape pattern that follows a given rule. Identify apparent features of the pattern that were not explicit in the rule itself. For example, given the rule "Add 3" and the starting number 1, generate terms in the resulting sequence and observe that the terms appear to alternate between odd and even numbers. Explain informally why the numbers will continue to alternate in this way. (CC.4.OA.5)

Resources

​http://www.mathantics.com/section/lesson-video/points-lines-planes Math Antics-Points

http://www.mathantics.com/section/lesson-video/angle-basics Math Antics- Angle Basics

http://www.mathantics.com/section/lesson-video/triangles Math Antics- Triangles

http://www.mathantics.com/section/lesson-video/quadrilaterals Math Antics- Quadrilaterals

https://www.youtube.com/watch?v=P3AOoLbA3us Lines Songs-Numberrock

https://www.youtube.com/watch?v=WMkY_uIku9Q Quadrilateral Song- Numberrock

https://www.youtube.com/watch?v=JQUTVgT9RXY Triangle Song-Numberrock

https://www.youtube.com/watch?v=NVuMULQjb3o Angle Song- Numberrock

https://www.youtube.com/watch?v=vEro2-qcFqU Symmetry