The height of an equilateral triangle of side is 10 3√ cm. calculate its perimeter.
20cm
60cm
40cm
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