The angles of a pentagon are x°, 2x°, (x + 60)°, (x + 10)°, (x -10)°. Find the value of x.
-
A.
40 -
B.
60 -
C.
75 -
D.
80 -
E.
90
Correct Answer: Option D
Explanation
Sum of ∠s in a pentagon = (n – 2)180 = 540°
x° + 2x° + x° + 60° + x° + 10° + x° – 10° = 540°
6x° + 60° = 540°; x = 80°