A) \[22\,sq.\,cm\]
B) \[25\,sq.\,cm\]
C) \[21\,sq.\,cm\]
D) \[24\,sq.\,cm\]
Correct Answer: C
Solution :
In \[\Delta AOB\]and \[\Delta COD,\] we have \[\angle AOB=\angle COD\] [Vertically opposite angles] \[\angle OAB=\angle OCD\] [Alternate interior angles]: \[\therefore \] \[\Delta \,AOB\tilde{\ }\Delta COD\] [By AA similarity] \[\Rightarrow \]\[\frac{ar(\Delta AOB)}{ar(\Delta COD)}=\frac{A{{B}^{2}}}{C{{D}^{2}}}=\frac{{{(2CD)}^{2}}}{C{{D}^{2}}}\] \[\left[ \because \,AB=2CD \right]\] \[\Rightarrow \]\[\frac{84}{ar\,(\Delta COD)}=\frac{4}{1}\]\[\Rightarrow \]\[ar(\Delta COD)=21\,sq.\,cm\]You need to login to perform this action.
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