Question

find area of a triangle whose two sides are 18 cm and 10cm and perimeter is 42cm step by step for class 9​

Answer 1

Find the length of the 3rd side:

3rd side = 42-18-10 = 14 cm

The two shorter sides are the base and the height.

Area of triangle = 1/2 x base height

Area =1/2 x 10 x 14

Area = 70 square cm