# Find the value of c in a triangle if the semi perimeter is 13 and the values of a and b are 8 and 7 respectively.

Given,

Semi perimeter of triangle, S = 13

a = 8

b = 7

c = ?

We know that semi perimeter of triangle is:

$S=frac{a+b+c}{2}$

a + b + c = 2S

8 + 7 + c = 2 x 13

c = 26 – 15 = 11

Therefore, the value of c is 11.