Question

In a pentagon, two angles are 40° and 60°, and the rest are in the ratio 1 : 3 : 7. Find the biggest angle of the pentagon.

Answer 1

In a pentagon, two angles are 40° and 60° Sum of remaining 3 angles = 3 x 180° 

= 540° – 40° – 60° = 540° – 100° = 440°

Ratio in these 3 angles =1 : 3 : 7

Sum of ratios =1 + 3 + 7 = 11

Biggest angle =`(440 xx 7)/11`= 280°