Solving for Unknown Angles

Student Summary

We can write equations that represent relationships between angles.

Three images. First, adjacent angles, x degrees, 42 degrees, form a straight line. Second, vertical angles, 28 degrees, y degrees. Third, complementary angles, z degrees, 64 degrees.

  • The first pair of angles are supplementary, so x+42=180x+42 = 180.
  • The second pair of angles are vertical angles, so y=28y = 28.
  • Assuming the third pair of angles form a right angle, they are complementary, so z+64=90z + 64 = 90.

Visual / Anchor Chart

Standards

Addressing
7.G.A

No additional information available.

7.G.5

Use facts about supplementary, complementary, vertical, and adjacent angles in a multi-step problem to write and solve simple equations for an unknown angle in a figure.

Building Toward
7.G.5

Use facts about supplementary, complementary, vertical, and adjacent angles in a multi-step problem to write and solve simple equations for an unknown angle in a figure.