Question 6
In ΔABC, if L and M are the points on AB and AC, respectively such that LM || BC. Prove that ar(ΔLOB)=ar(ΔMOC).
We know that triangles on the same base and between the same parallels are equal in area.
Hence, ΔLBC and ΔMBC lie on the same base BC and between the same parallels BC and LM.
So, ar(ΔLBC)=ar(ΔMBC)
⇒ar(ΔLOB)+ar(ΔBOC)=ar(ΔMOC)+ar(ΔBOC)
On eliminating ar(ΔBOC) from both sides, we get,
ar(ΔLOB)=ar(ΔMOC)