Given:△ABCwhereD,E,FarethemidpointsofthesidesBC,CAandABof△ABC.ToProve:XY=14BCProof:In△ABC,FandEarethemidpointsofABandACrespectively∴FE∥BCandFE=12BC=BD(Thelinejoiningthemid−pointsoftwosidesofatriangleisparalleltothethirdsideandequaltohalfthelengthofthethirdside)∴FE∥BDandFE=BD.HenceBDEFisaparallelogramwhosediagonalsBEandDFintersecteachotheratX)∴XisthemidpointofDF.Similarly,YisthemidpointofDE.Thus,in△DEF,XandYarethemidpointsofDFandDErespectively.So,XY∥FEandXY=d12FE(MidpointTheorm)=12×12BC=14BCHenceProved