Question

The four angles of a quadrilateral are in the ratio 2:4:5:7. Find the largest angle.

• A. ${140}^o$
• B. ${160}^o$
• C. ${90}^o$
• D. ${120}^o$

Answer 1

The correct option is A ${140}^o$

Let the angles be 2x, 4x, 5x, 7x.
Thus, 2x + 4x + 5x + 7x = 360°
Sum of the angles of a quadrilateral is 360°.
So, 18x = 360°
Or, x = 20°
Thus, the largest angle is 140°.