In the given fig, D is a point on the side BC of ∆ABC such that ∠ADC = ∠BAC. Prove that   or  CA2 = CB.CD.
Diagonals of a trapezium ABCD with AB || DC intersect each other at the point O.If AB = 2 CD, find the ratio of the areas of triangles AOB and COD.
In the given fig, ABC and DBC are two triangles on the same base BC. If AD intersects BC at O, show that