In a ΔABC, M and N are points on the sides AB and AC respectively such that BM = CN. If ∠B=∠C then show that MN || BC.
AB=AC (since∠B=∠C) ....(1)
BM=CN (given)
from 1 , AM+MB = AN +NC
AM=AN ( MB=NC)
AMBM =ANNC
since MN is dividing the sides AB and AC in proportion , by Basic proportionality theorem MN || BC