The altitude of an equilateral triangle is 4.2 meters long. Find the perimeter of the triangle.

Answer 1

x is the measure of the side of the equilateral.

z = x/2

tan 60 = 4.2/ z

Solves for z:

z = 4.2 / tan 60 =

4.2 / sqrt(3) <--- tan 60 is sqrt(3)

4.2 * sqrt(3)/ 3 <--- rationalizes the denominator

x = 8.4*sqrt(3)/3 <--- doubles that to get side of the triangle

multiplies that by 3:

perimeter is 8.4*sqrt(3)

which is APPROXIMATELY 14.55-