Subscribe

7th grade · Math · Unit 15 of 17

Angle Relationships

Complementary, supplementary, vertical

What your child practices

Using complementary, supplementary, vertical and adjacent angles to find a missing angle, sometimes with a simple equation.

Washington State Learning Standards learning standard: M.7.SR.G.5 · using supplementary, complementary, vertical and adjacent angles to write and solve equations for unknown angles

How we explain it

Children can open this short lesson before they practice.

  1. Complementary angles add to 90°. Supplementary angles add to 180°.
  2. Vertical angles (opposite when lines cross) are equal.
  3. Write an equation and solve for the missing angle.

Example: Two angles are supplementary. One is 65°. What is the other? 180 − 65 = 115. Answer: 115°

Sample questions

A taste of this unit. In the app, questions change every time and get easier or harder to match your child.

  1. Question 1

    Two angles are supplementary. One is x and the other is 5x. What is x?

    • 150°
    • 40°
    • 36°
    • 30°

  2. Question 2

    Three angles sit side by side on a straight line. Two of them are 27° and 23°. What is the third?

    • 67°
    • 50°
    • 130°
    • 310°

  3. Question 3

    Two angles are complementary. One is 53°. What is the other?

    • 53°
    • 37°
    • 34°
    • 127°

  4. Question 4

    Two lines cross. One angle is 45°. What is the angle vertically opposite to it?

    • 45°
    • 135°
    • 315°
    • 44°

  5. Question 5

    Two angles are supplementary. One is x and the other is 5x. What is x?

    • 30°
    • 150°
    • 36°
    • 40°

  6. Question 6

    Two lines cross. One angle is 131°. What is the angle next to it on the same line?

    • 50°
    • 49°
    • 131°
    • 229°

More 7th grade