The median BD is drawn in the isosceles triangle ΔABC. Point N is marked on the median. Prove the equality of triangles ΔABN and ΔBNC

In the isosceles triangle ABC, the median BD was drawn, which is also the bisector and height.
AB = BC (these sides are equal in an isosceles triangle)
BN is the common side for triangles ABN and BNC
Since BD is the median, bisector and height, it divides angle B into two equal ones (angle ABN and angle CBN)
Found 3 equal elements, it follows that triangle ABN is equal to triangle CBN