Angle Addition Problems

Answer Key - Grade 4 Math Worksheet - Challenge Me

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

1. 1.

   Two angles sit side by side on a straight line, so together they make 180°. One angle is 57°. What does the other angle measure?

   123
2. 2.

   Three angles share a corner and together make a right angle (90°). Two of them measure 31° and 18°. What does the third angle measure?

   41
3. 3.

   An 85° angle is split into a 34° part and an unknown part, x. Which equation finds x?

   • 34 − x = 85
   • 85 + 34 = x
   • x − 34 = 85
   • 85 − 34 = x
4. 4.

   A lamp must turn 161° in all. It turns 56°, then 55°. How many more degrees must it turn?

   50
5. 5.

   The whole angle measures 144°. One part measures 54°. What does the part marked ? measure?

   90
6. 6.

   Three angles share a corner and together make a straight angle (180°). Two of them measure 36° and 97°. What does the third angle measure?

   47
7. 7.

   An angle is split into two parts of 48° and 43°. What does the whole angle measure?

   91
8. 8.

   A robot arm must turn 97° in all. It turns 32°, then 31°. How many more degrees must it turn?

   34
9. 9.

   A 159° angle is split into an 112° part and an unknown part, x. Which equation finds x?

   • x − 112 = 159
   • 159 − 112 = x
   • 112 − x = 159
   • 159 + 112 = x
10. 10.

    Two angles sit side by side on a straight line, so together they make 180°. One angle is 64°. What does the other angle measure?

    116