Question

the sum of all interior angles of a regular polygon is 1260 degree then the number of sides and diagonals espectively are?
please solve fast.​

Answer 1

Answer:

8, 20

Step-by-step explanation:

We know, that if the no. of sides of a polygon is n, then sum of all interior angles = (n-1)*180°

Given,

(n-1)*180° = 1260°

=> n-1 = 7  => n = 8.

Therefore, no. of sides = 8.

If no. of sides = n, then no. of diagonals = n(n-3)/2

Therefore, no. of diagonals = 8*5/2 = 20