The angles of a quadrilateral are in the ratio 1:2:3:4. What is the measure of the largest angle?
Answer: D
The sum of the interior angles of a quadrilateral is 360°.
Let the angles be x, 2x, 3x, and 4x.
x + 2x + 3x + 4x = 360°
10x = 360°
x = 36°.
The largest angle is 4x = 4 × 36° = 144°.