Question

What is the value of x? (HINT: find the sum of the
interior angles of the pentagon first)

Answer 1

(2x+10°) + (x°) +(2x-20°) = 540°

540 is the sum angle of the polygon

collect like terms

2x+x+2x+10°-20°=540°

5x-10°=540°

5x=540°+10°

5x=550°

x=550°/5

x=110°

(2(110)+10)+(110)+(2(110)-20)=540°