D is a point on the side BC of a triangleABC such that ∠ ADC = ∠ BAC. Show that CA2 = CB.CD
In ΔADC and ΔBAC,
∠ADC = ∠BAC (Given)
∠ACD = ∠BCA (Common angle)
ΔADC ΔBAC (By AA similarity)
We know that corresponding sides of similar triangles are in proportion
Hence,
CA2 = CB * CD