Question 13
A polygon has prime number of sides. Its number of sides is equal to the sum of the two least consecutive primes. The number of diagonals of the polygon is
a) 4
b) 5
c) 7
d) 10
The two least consecutive primes numbers are 2 and 3.
∴ 2 + 3 = 5
So,the total number of sides of polygon (n) = 5
∴ Number of diagonals = n(n−3)2
= 5(5−3)2
= 102
= 5