Question 951150
Pythagorean Theorem and understanding the symmetrical nature of an equilateral triangle.  Drawing one altitude separates the equilateral triangle into two special 30-60-90 right triangles.  If short leg of either such triangle is x, the hypotenuse is 2x.  Use Pythagorean Theorem formula to find the length of the longer leg, which is here the same as the altitude of the equilateral triangle.


Now in your example, 2x=16.


You should draw the figure, and you should form the equation and solve it.