Indiana Academic Standards
4.G.3. Recognize angles as geometric shapes that are formed wherever two rays share a common endpoint.
4.G.4. Identify, describe, and draw rays, angles (right, acute, obtuse), and perpendicular and parallel lines using appropriate tools (e.g., ruler, straightedge and technology). Identify these in two-dimensional figures.
4.M.5. Understand that 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. Understand an angle that turns through 1/360 of a circle is called a “one-degree angle,” and can be used to measure other angles. Understand an angle that turns through n one-degree angles is said to have an angle measure of n degrees.
4.M.6. Measure angles in whole-number degrees using appropriate tools. Sketch angles of specified measure.