Question

Three interior angles of a quadrilateral measure 55° 117° and 120° what is the measure of the fourth interior angle.

68 degrees
78 degrees
88 degrees
98degrees

Answer 1

`\boxed{x \degree = 68 \degree}`

Given:

Measure of three interior angles of a quadrilateral is 55° , 117° and 120°

Explanation:

Let the fourth interior angle be 'x'

The Interior Angles of a Quadrilateral add up to 360°

`= > x \degree + 55 \degree + 117 \degree + 120 \degree = 360 \degree \\ \\ = > x \degree + 172 \degree + 120 \degree = 360 \degree \\ \\ = > x \degree + 292 \degree = 360 \degree \\ \\ = > x \degree = 360 \degree - 292 \degree \\ \\ = > x \degree = 68 \degree`