The sum of the interior angle of pentagon is 6x + 6y. Find y in terms of x.
A
y = 6 - x
B
y = 90 - x
C
y = 120 - x
D
y = 150 - x
Verified Correct Answer: B.
Step-by-Step Mathematical Solution
Sum of interior angles = (2n - 4) 90\(^o\)
For perntagon, n = 5
Sum of interior angles = 6 x 90\(^o\) = 540\(^o\)
6x + 6y = 540\(^o\)
6(x + y) = 540\(^o\)
x + y = \(\frac{540^o}{6}\) = 90\(^o\)
y = 90\(^o\)
y = 90 - x
Source: Myschool Past Questions Archive (Record #56861)