Angle Addition Problems

Answer Key - Grade 4 Math Worksheet - Building Confidence

Write the answer on the line, or circle the answer.

1. 1.

   The whole angle measures 90°. One part measures 60°. What does the part marked ? measure?

   30
2. 2.

   An angle is split into two parts of 30° and 30°. What does the whole angle measure?

   60
3. 3.

   The whole angle measures 60°. One part measures 25°. What does the part marked ? measure?

   35
4. 4.

   A robot arm turns 75°. Then it turns 45° more in the same direction. How many degrees has it turned in all?

   120
5. 5.

   An angle is split into two parts of 20° and 40°. What does the whole angle measure?

   60
6. 6.

   The whole angle measures 90°. One part measures 50°. What does the part marked ? measure?

   40
7. 7.

   A 120° angle is split into an 85° part and an unknown part, x. Which equation finds x?

   • 120 − 85 = x
   • x − 85 = 120
   • 85 − x = 120
8. 8.

   An angle is split into two parts of 45° and 15°. What does the whole angle measure?

   60
9. 9.

   The whole angle measures 60°. One part measures 35°. What does the part marked ? measure?

   25
10. 10.

    A robot arm turns 40°. Then it turns 80° more in the same direction. How many degrees has it turned in all?

    120