Illustrative Mathematics
Finding an Unknown Angle
Teach your class how to apply their knowledge of geometry as they explore the unknown. In order to find an unknown angle, learners must understand that rectangles have four interior right angles, that right angles have 90 degrees, and...
Khan Academy
Khan Academy: Equation Practice With Angles
In this practice activity, students calculate angles created when two parallel lines are intersected by a transversal. Students receive immediate feedback and have the opportunity to watch a video, get hints, or try questions repeatedly.
Khan Academy
Khan Academy: Angle Relationships With Parallel Lines
Find missing angles given two parallel lines and a transversal. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video, or receive hints.
Khan Academy
Khan Academy: Finding Angle Measures Using Triangles
Use your knowledge of angles to find missing angle measures in various complex situations. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video, or receive hints.
Khan Academy
Khan Academy: Find Angles in Triangles
Find missing angle measures using the properties of triangles. Students receive immediate feedback and have the opportunity to try questions repeatedly, watch a video, or receive hints.
Free Math Help
Free Math Help: Exterior Angle of a Triangle
This tutorial discusses exterior angles of a triangle. Example problems with explanations are included.