Question

the side of an equilateral triangle = 60cm, semi perimeter= 90 cm, then find the area by Heron's formula

Answer 1

Step-by-step explanation:

Perimeter = 60cm 

1 side = 60/3 = 20 cm

√s(s-a)(s-b)(s-c)s(s−a)(s−b)(s−c)

s = 30 

√30(30-20)(30-20)(30-20)

=√30×10×10×10=√30000cm² = 100√3 cm²