Question

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

Answer 1

Explanation:

s = √( 4.2*4.2 + (s/2)(s/2) )

s = √( 4.2*4.2 + (s^2/4) )

s^2= 4.2*4.2 + (s^2/4)

s^2 - (s^2/4) = 4.2*4.2

(4s^2/4) - (s^2/4) = 4.2*4.2

(3s^2/4) = 4.2*4.2

(3/4)s^2 = 4.2*4.2

s^2= 4.2*4.2*(4/3)

s = √( 4.2*4.2*(4/3) )

s = 2*4.2 * √( 1/3 )

s = 4.84974226119

answer:

perimeter = 3 * 4.84974226119

perimeter = 14.5492267836 meters