Question 423468
when an equilateral triangle is sitting on one of the sides, the altitude to the opposite vertex bisects the side
___ this divides the triangle into two 30-60-90 right triangles


if the length of a side of the equilateral triangle is "s",
then the altitude (which is one of the 30-60-90 sides) is {[s * sqrt(3)] / 2}


using the triangle area formula (1/2 * b * h) ___ (1/2)(s){[s * sqrt(3)] / 2}


the area is ___ [(s^2) * sqrt(3)] / 4