In the given figure, AB=BC and AD=BD=DC. The number of isosceles triangles in the figure is
1
2
3
4
We have three isosceles triangles.
∆ABC is an isosceles triangle with AB=BC
∆ABD is an isosceles triangle with AD=BD
∆BCD is an isosceles triangle with DC=BD
In ΔABC, AD is the perpendicular bisector of BC (see the given figure). Show that ΔABC is an isosceles triangle in which AB = AC.