Unit 8 Overview:

This unit is an introduction to angles and angle measurement. Students use their understanding of equal partitioning and unit measurement to understand angle/turn/rotation measure. They will measure angles, decompose and compose angles to model the additive nature of angles, and solve real world and mathematical problems to find the measurement of unknown angles.

• Students will recognize angles as geometric shapes that are formed wherever two rays share a common endpoint; and understand concepts of angle measurement: An angle is measured with reference to a circle with its center at the common endpoint of the rays, by considering the fraction of the circular arc between the points where the two rays intersect the circle. An angle that turns through 1/360 of a circle is called a “one-degree angle,” and can be used to measure angles. (MD.C.5a)
• Students will recognize angles as geometric shapes that are formed wherever two rays share a common endpoint; and understand concepts of angle measurement: An angle that turns through n one-degree angles is said to have an angle measure of n degrees. (MD.C.5b)
• Students will measure angles in whole-number degrees using a protractor. Sketch angles of specified measures. (MD.C.6)
• Students will recognize angle measure as additive. When an angle is decomposed into non-overlapping parts, the angle measure of the whole is the sum of the angle measures of the parts. Solve addition and subtraction problems to find unknown angles on the diagram in real world and mathematical problems, eg., by using an equation with a symbol for the unknown angle measure. (MD.C.7)
• Students will draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures. (G.A.1)
• Students will 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. (G.A.2) (Unit 8)
• Students will recognize a line of symmetry for two-dimensional figure as a line across the figure such that the figure such that the figure can be folded along the line into matching parts. Identify line-symmetric figures and draw lines of symmetry. (G.A.3)