Grade 8 - Geometry
Standard 8.G.5 - Use the fact that the angle sum of triangles is 180º and quadrilaterals is 360º to find the missing interior angle.
Included Skills: Geometry
Use informal arguments to establish facts about the angle sum and exterior angle of triangles, about the angles created when parallel lines are cut by a transversal, and the angle-angle criterion for similarity of triangles.