A) 30
B) 40
C) 50
D) 60
Correct Answer: D
Solution :
Length of diagonal = \[52\times \frac{15}{60}=1\] Length along sides = \[68\times \frac{15}{60}=17m\] Now, l + b = 17 and \[\sqrt{{{l}^{2}}+{{b}^{2}}}\]= 13 \[\begin{align} & \Rightarrow \,\,\,\,\,\,\,\,\,\sqrt{{{l}^{2}}+{{b}^{2}}}=169 \\ & \Rightarrow \,\,\,\,\,\,\,\,\,{{(17-b)}^{2}}+{{b}^{2}}=169 \\ \end{align}\] \[\Rightarrow \,\,\,\,\,\,\,\,\,289-34b+2{{b}^{2}}=169\] \[\begin{align} & \Rightarrow \,\,\,\,\,\,\,\,\,{{b}^{2}}-17b+60=0 \\ & \Rightarrow \,\,\,\,\,\,\,\,\,(b-12)\left( b-5 \right)=0 \\ & \Rightarrow \,\,\,\,\,\,\,\,\,b=5,12\Rightarrow l=12,5 \\ \end{align}\] \[\therefore \] Area of the ground =12 x 5= 60m2You need to login to perform this action.
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