Question

If the sum of three angles of a quadrilateral is 300°. Find the measure of fourth angle.

• A. 30°
• B. 45°
• C. 60°
• D. 90°

Answer 1

The correct option is C 60°

$\text{We know that by angle sum property,}\text{the sum of internal angles of a}\text{quadrilateral}={360}^{\circ }$

$\text{Let the unknown angle be}x.$

$\text{So,}{300}^{\circ }+x={360}^{\circ }x={360}^{\circ }-{300}^{\circ }x={60}^{\circ }$

$\text{The fourth angle is}{60}^{\circ }.$