Question

Using heron's formula find the area of an equilateral triangle whose perimeter is 60cm

Answer 1

perimeter of equilateral triangle=3× a side
so, side=60/3
=20cm

now semi-perimeter=30cm

therefore, area of triangle by heron's formula=√s(s-a)(s-b)(s-c)
=√30×(30-20)(30-20)(30-20)
=√30×10×10×10
=100√3cm^2 answer