Example 4

This Instructional Activity is a part of the Lesson 11, Unit 3, Grade 7. Students use vertical angles, adjacent angles, angles on a line, and angles at a point in a multi-step problem to write and solve simple equations for an unknown angle in a figure. At the heart of each problem is the need to model the angle relationships in an equation and then solve for the unknown angle. The diagrams are all drawn to scale; students should verify their answers by using a protractor to measure relevant angles.