Question

Find the area of a triangle two sides of which are 18 cm and 10 cm and the perimeter is 42 cm.

Answer 1

Here a = 18 cm, b = 10 cm, c = ? 

Perimeter of the triangle = 42 cm 

⇒ a + b + c = 42 

⇒ 18 + 10 + c = 42 

⇒ c = 42 – 28 = 14 

ow, s = a + b+ c/ 2 =  42/ 2 cm = 21 cm