# ISEE Upper Level Math : How to find an angle in other quadrilaterals

## Example Questions

### Example Question #1 : How To Find An Angle In Other Quadrilaterals

Three of the interior angles of a quadrilateral measure , and . What is the measure of the fourth interior angle?

Explanation:

The measures of the angles of a quadrilateral have sum . If  is the measure of the unknown angle, then:

The angle measures .

### Example Question #2 : How To Find An Angle In Other Quadrilaterals

The angles of a quadrilateral measure . Evaluate .

Explanation:

The sum of the degree measures of the angles of a quadrilateral is 360, so we can set up and solve for  in the equation:

### Example Question #3 : How To Find An Angle In Other Quadrilaterals

The four angles of a quadrilateral have the following value: 79 degrees, 100 degrees, 50 degrees, and  degrees. What is the value of ?

Explanation:

Given that there are 360 degrees when all the angles of a quadrilateral are added toghether, this problem can be solved with the following equation:

### Example Question #4 : How To Find An Angle In Other Quadrilaterals

In a quadrilateral, the angles have the following values:

What is the value of ?