Question

Two sides of a triangle are 13cm 14cm and its semi perimeter is 18cm then what will be the third side of triangle

Answer 1

lets take a = 13, b = 14, c = x ;
$s = (a + b + c) \div 2$

putting in the values ,

18 = (13+14+x)/2;
36 = 27 + x
9 = x

so, the required side is of 9 cm.

Answer 2

Semi-perimeter = 18 cm

Find Perimeter:

Perimeter = Semi-perimeter x 2

Perimeter = 18 x 2 = 36 cm

Find the third sides:

Perimeter = side 1 + side 2 + side 3

36 = 13 + 14 + x

x = 36 - 13 - 14

x = 9 cm

Answer: The third side is 9 cm