D is the midpoint f side BC of △ABC and E is the midpoint of BD. IF O is the midpoint of AE, prove that ar (△BOE)=18ar(△ABC)
In △ABC, D is mid point of BC, E is mid point BE and O is the midpoint of AE. BO, AE, AD are joined.
To prove : ar (△BOE)=18ar(△ABC)
Proof: In △ABC,
∴ D is the midpoint of BC
ar(△ABD)=ar(△ADC)=12ar(△ABC)In△ABD,E is the midpoint of BD∴ar(△ABE)=12ar(△ABD)=12(12ar(△ABC))=14ar(△ABC)∵O is the midpoint of AE∴ar(△BOE)=12ar(△ABE)=12×(14ar(△ABC))=18ar(△ABC)Hencear(△BOE)=18ar(△ABC)