Question 133998
the altitude of an equilateral triangle forms a 30-60-90 right triangle with one of the sides and half the base


if x equals a side, the altitude is equal to (x/2)(sqrt(3))


so the area is (1/2)(x)(x/2)(sqrt(3))


(x^2/4)(sqrt(3))=100 __ x^2=400/(sqrt(3)) __ x=sqrt(400/(sqrt(3)))