ABC is a triangle in which AB = Ac and D is a point on the side AC such that BC2 = AC × CD. Prove that BD = BC.
Answers:
Given: A △ABC in which AB = AC. D is a point on AC such that BC2 = AC × CD.
To prove : BD = BC
Proof : Since BC2 = AC × CD
Therefore BC × BC = AC × CD
AC/BC = BC/CD …….(i)
Also ∠ACB = ∠BCD
Since △ABC ~ △BDC [By SAS Axiom of similar triangles]
AB/AC = BD/BC ……..(ii)
But AB = AC (Given) ………(iii)
From (i),(ii) and (iii) we get
BD = BC.