This fits the standard of CCSS.MATH.CONTENT4.G.A.1-2. 1 says, Draw points, lines, line segments, rays, angles (right, acute, obtuse), and perpendicular and parallel lines. Identify these in two-dimensional figures. 2 says, 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. These both address angle sizes and measuring the value of the 3 angle triangles and not line triangles.
