D is any point on side AC of an ABC with AB = AC. Show that CD < BD.
Given: ABC is a triangle and D is any point on AC.
AB = AC
To prove CD < BD.
Proof: In ABC
AB = AC (Given)
ABC =
ACB (angles opposite to equal sides are equal)
In ABC and
DBC
ABC >
DBC
ACB >
DBC
BD > CD (Side opposite to greater angle is larger)
CD < BD
Hence proved.