In the diagram, AABC has D on BC, E on AC, and F on AB. Point P is the point of intersection of AD and BE, point Q is the point of intersection of AD and CF, and point R is the point of intersection of BE and CF. Suppose that BD : DC = 1 : 1, AE : EC = 1 : 2, and BF : FA = 1 : 3. A E P F R O B D (a) Prove that the area of APQB is equal to the area of APQC. (b) Prove that the area of CRB is twice to the area of A ARB. (c) If the area of APQR equals 25, determine the area of AABC