
CHAPTER 10: TWODIMENSIONAL 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
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)
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 twodimensional figures. (CC.4.G.1)
2. Classify twodimensional 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 twodimensional figure as a line across the figure such that the figure can be folded along the line into matching parts. Identify linesymmetric 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)

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 SolvingShape Patterns (CC.4.OA.5)^
* created by Alden JackNorth Park Elementary
^ created by Holly StuartNorth Park Elementary