A triangle ABC is given, and a segment PQ=t on BC such that P is between B and Q and Q is between P and C. Let PP1∣∣AB, P1 is on AC, and PP2∣∣AC, P2 is on AB. Points Q1 and Q2 аrе defined similar. Prove that the sum of the areas of PQQ1P1 and PQQ2P2 does not depend from the position of PQ on BC. geometrygeometry proposed