A polygon has 135 diagonals. How many sides does it have?
Self made  Choose the most appropriate option.
A) 12	B) 13	C) 18	D) 15	E) 16
The best way to solve this problem is to use the formula: An n sided polygon can have n*(n - 3)/2 diagonals   n*(n - 3)/2 = 135   n*(n - 3) = 270   Substitute n from the answer choices. n = 18   Answer: 18
<result>C</result>
A polygon has 135 diagonals. How many sides does it have?
Self made