∠BAC of △ABC is obtuse and AB=AC. P is a point on BC such that PC=12 cm. PQ and PR are perpendiculars to sides AB and AC respectively. If PQ=15 cm and PR=9 cm, then the length of PB (cm) is
In triangle ABC, AB = AC = 8 cm, BC = 4 cm and P is a point in side AC such that AP = 6 cm. Prove that Δ BPC is similar to Δ ABC. Also, find the length of BP.