Question

if the perimetre of an equilateral triangle is 60 cm then what is its area​

Answer 1

Answer:

perimeter=60cm

We know that all sides of an equilateral triangle are equal

therefore one side=20cm

Step-by-step explanation:

S=a+b+c/2

S=20+20+20/2

S=60/2

S=30cm

by herons formula:√S(S-a)(S-b)(S-c)

=√30(30-20)(30-20)(30-20)

=√30×10×10×10

=√10×3×10×10×10

=10×10√3

=100√3 cm^2

therefore,the area of the equilateral triangle is 100√3 cm^2