The height of an equilateral triangle of side is 10 3√ cm. calculate its perimeter.

A.

20cm

B.

60cm

C.

40cm

D.

30cm

Correct answer is B

Height of an equilateral triangle, h = a\(\frac{√3}{2}\), where a is the side of the equilateral triangle.

10√3 = a\(\frac{√3}{2}\)

cross multiply--> 2 * 10√3 = a√3

√3 strikes √3 on both sides

20 = a

The perimeter of an equilateral triangle is: P = 3a

P = 3 * 20 = 60cm

P = 30√3