Question 594389
picture an equilateral triangle (60-60-60)


a perpendicular bisector of the base divides the equilateral into two 30-60-90 triangles


if the shorter side (half the base) is P, then the hypotenuse (one of the other equilateral sides) is 2P


using Pythagoras to find the longer leg ___ P^2 + x^2 = (2P)^2 ___ x^2 = 3P^2 ___ x = P√3