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ABCD is a square. E and F are respective...

ABCD is a square. E and F are respectively the mid-points of BC and CD. If R is the mid-point of EF, prove that `ar (DeltaAER) = ar (DeltaAFR)`.

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Given In square ABCD, E and F are mid-points of BC and CD respectively. Also, R is the mid-point of EF.

To prove `ar (AER) = ar (AFR)`
Construction Draw `AN bot EF`
Proof `because` `" " ar (DeltaAER) = (1)/(2) xx "Base" xx "Height"`
`= (1)/(2) xx ER xx AN`
`= (1)/(2) xx FR xx AN" "` [`because` R is the mid-point of EF, so ER = FR]
`= ar (DeltaAFR)" "` Hence proved.
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