To prove:- AC2=AD×AE
Proof:-
From the given fig., in △ACD and △AEC,
As we know that if a perpendicular is drawn from the vertex of the right angle to the hypotenuse then triangles on both sides of the perpendicular are similar to the whole triangle and to each other.
∴△ACD∼△AEC
Also, if two triangles are similar, then the ratio of their corresponding sides are also equal.
Therefore,
ACAE=ADAC
⇒AC2=AD×AE
Hence proved.