Question

The number of diagonals of a polygon is twice the number of its sides. Find the number of sides of the polygon.

Answer 1

Answer:

Step-by-step explanation:

Let the no. of sides be n.

We know, no. of diagonals of a polygon = n(n-3)/2

So, n(n-3)/2 = 2n

=> n² - 3n = 4n

=> n² - 7n = 0

=> n - 7 = 0

=> n = 7