I think you mean the angles all are 60 degrees, not 90. Anyway, if you draw the altitude and focus on the right side of the equilateral triangle, you should see that: where x is your altitude. You should be able to solve for x.
What is the altitude of an equilateral triangle with side of 4.0m?
ok I know all sides and angles are equal. so i drew a triangle with all sides of 4.0 and all angles of 90. then I divided it vertically to get the altitude. which would give me a side of 4.0m, a side of 2.0m, a 90 angle and a 45 angle. I do not know how to set this up to solve. i am looking for the hypotenuse but just can't seem to find the right way to set up