A polygon has a total of 35 diagonals. How many sides does the polygon have?
Show answer & explanation
Correct answer: D
Explanation
Number of diagonals = 35
Diagonals = n(n − 3)/2
n(n − 3)/2 = 35
n(n − 3) = 70
n² − 3n − 70 = 0
(n − 10)(n + 7) = 0
n = 10 sides