In △MNS, line KL ∥ side NS .....(given)∴MKKN=MLLS ..... (By BPT)
But MK=KN∴MKKN=1
∴MLLS=1
∴ML=LSThis means that line KL bisects side MS.
Using Basic proportionality theorem, prove that a line drawn through the mid-point of one side of a triangle parallel to another side bisects the third side. (Recall that you have proved it in Class IX).