# GED Math : Complementary Angles

## Example Questions

### Example Question #461 : 2 Dimensional Geometry

Use the following angles to answer the question:

If these two angles are complementary, find the value of x

Explanation:

Two angles are complementary if they add up to . So, we can use the formula

where x and y are the angles.

So, given the angles

we can see one angle is . So, we can substitute and solve for x. We get

### Example Question #462 : 2 Dimensional Geometry

If angle measure is  degrees, what is the other angle if both angles are complementary?

Explanation:

Complementary angles add up to 90 degrees.

To determine the other angle, subtract 81 from 90.

### Example Question #463 : 2 Dimensional Geometry

If two angles are complementary, and one angle is , what is the value of the other angle?

Explanation:

Two angles are complementary if they add up to . We can use the formula:

where x and y are the angles.

Now, we know one angle is . So, we will substitute and solve for the other angle. We get

### Example Question #464 : 2 Dimensional Geometry

If an angle is measured 35 degrees, what is the other angle if both angles are complementary?

Explanation:

Complementary angles sum up to 90 degrees.

To find the other angle, subtract the known angle from 90 degrees.

### Example Question #465 : 2 Dimensional Geometry

Suppose two angles are complementary.  What must  be if the angles are  and  degrees?

Explanation:

The sum of both angles must add up to 90 degrees.

Solve for the variable.

Divide by 10 on both sides.

Simplify the fraction.

### Example Question #466 : 2 Dimensional Geometry

If two angles are complementary, and one angle is measured  radians, what is the other angle in radians?

Explanation:

If the set of angles are complementary, they must add up to  radians, which is equivalent to 90 degrees.

### Example Question #467 : 2 Dimensional Geometry

Which angle is complementary to 30 degrees?

Explanation:

Complementary angles must sum up to 90 degrees. In order to find the other angle, we must subtract the given angle from 90 degrees.

### Example Question #468 : 2 Dimensional Geometry

Which of the following pairs of angles are complementary angles?

Explanation:

Which of the following pairs of angles are complementary angles?

Recall that complementary angles are angles which add up to 90 degrees.

In this case, all we have to do is see which pairs sum to 90, and that will be our answer:

So it must be the last one.

### Example Question #469 : 2 Dimensional Geometry

Right triangle has right angle and angle . What would be the measure of an angle which is complementary to ?

Explanation:

No calculation is actually required for this problem. is the right angle of , so and must comprise a complementary pair of angles. Since is complementary to , any angle complementary to  must have measure equal to that of , which is .

### Example Question #470 : 2 Dimensional Geometry

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If the sum of two angles results in a complementary angle, what is the measure of the unknown angle?