Problem 212. 120 Degree Triangle, Equilateral triangles, Areas
In the figure below, given a triangle
ABC of area S, the measure of the angle ABC is 120 degree and
ABD, BCE, and ACF are equilateral triangles of areas Sc, Sa, and Sb respectively. Prove that
(1) Sb = Sa + Sc + S, and (2)
. View or post a solution.