The altitude of an equilateral triangle is 9. Calculate the length of each side of the equilateral triangle. Leave your answer in simple radical form

Think of the altitude as a line that divides the equilateral triangle into two equal parts.

Each part is a 30, 60, 90 triangle. The altitude of the triangle corresponds to the x side of the equilateral triangle.

So: 9=x , and x=9/.

However, one side of the triangle is actually 2x, so the correct answer is

18/

Let me know if this helps!