ABC is an acute-angle triangle. Let P, Q, and R be the feet of the altitude from vertices A, C, and B, respectively, and all three altitudes intersect at O, then prove that β πππ = β πππ .
ABC is an acute-angle triangle. Let P, Q, and R be the feet of the altitude from vertices A, C, and B, respectively, and all three altitudes intersect at O, then prove that β πππ = β πππ .