Question

What is the height of an equilateral triangle with side lengths of 15? round to tenths?

Answer 1

If this is an equilateral triangle, we need half of it to find the height which is a leg of a right triangle with a hypotenuse of 15.  That means that the base of this half triangle is 7.5.  Use Pythagorean's Theorem to fine the height.  $x^{2} =(15) ^{2} -(7.5) ^{2}$.  x = 12.99 or 13