how many internal diagonals does a octagon (eight sided polygon) have?
Choose one:
A) 90 B) 85 C) 70 D) 35 E) 20

Rationale: number of diagonals in any polygon can be found using this formula : n ( n - 3 ) / 2 here n = 8 no . of diagonals = 8 ( 8 - 3 ) / 2 = 20 ans e
Answer: E