Question

in a pentagon two angles are 40 degree and 60 degree and the rest are in the ratio 1 :3 :7 find the biggest angle of the Pentagon​

Answer 1

The total angle sum =540°

40°+60°+x+3x+7x=540°

100°+11x=540°

11x=440°

x=40°

so the biggest angle is 7x=7*40=280

Answer 2

40+60+1x+3x+7x=(n-2) 180

=>100+11x=(5-2) 180

=>100 +11x=3×180

=>11x=540-100

=>x=440/11

=>x=40

=>3x=40×3=120

=>7x=40×7=280