Common Core Math Standard 8.G.5

Common Core Math Standard

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. For example, arrange three copies of the same triangle so that the sum of the three angles appears to form a line, and give an argument in terms of transversals why this is so.

Instructional Videos

Informative Websites

Illinois Teach and Talk | Khan Academy | Mr. Hill’s Math

Online Games

Calculate Angles | Shape Shoot​ | Angle Pairs

Words to Know