Question

An isosceles triangle has perimeter 30 cm and each of the equal sides is 12 cm. Find the area of the triangle. ​

Answer 1

Answer:

A≈40.25cm²

b Base

12

cm

P Perimeter

30

cm

Answer 2

SOLUTION

Length of the equal sides = 12cm

Perimeter of the triangle = 30cm

Length of the third side = 30 - (12+12) cm = 6cm

Semi perimeter of the triangle(s) = 30/2 cm = 15cm

Using heron's formula,

Area of the triangle = √s (s-a) (s-b) (s-c)

                                      = √15(15 - 12) (15 - 12) (15 - 6)cm2

                                      = √15 × 3 × 3 × 9 cm2

                                      = 9√15 cm2