How to Find the Complement of an Angle

Step-by-step solution

1. Recall the complementary-angle rule.

   $$A + B = 90^\circ$$

   Why: Two angles are complementary when they add to a right angle.

2. Substitute the known angle.

   $$37^\circ + B = 90^\circ$$

   Why: The known angle takes the place of A.

3. Subtract from 90.

   $$B = 90^\circ - 37^\circ = 53^\circ$$

   Why: Subtracting gives the missing partner.

Practice problems

Use the same method. Work each problem on paper, then open the answer to check.

1. 1

   $\text{complement of } 25^\circ$

   Show answer

   $65^\circ$

2. 2

   $\text{complement of } 48^\circ$

   Show answer

   $42^\circ$

3. 3

   $\text{complement of } 12^\circ$

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   $78^\circ$

4. 4

   $\text{complement of } 60^\circ$

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   $30^\circ$

5. 5

   $\text{complement of } 44^\circ$

   Show answer

   $46^\circ$