A) 13 cm
B) 69 cm
C) 26 cm
D) 23 cm
Correct Answer: A
Solution :
\[{{r}^{2}}=O{{M}^{2}}+M{{D}^{2}}\] \[{{r}^{2}}={{12}^{2}}+{{x}^{2}}\] ?(i) In \[\Delta OLB,\] \[{{r}^{2}}=L{{B}^{2}}+O{{L}^{2}}\] \[{{r}^{2}}={{(17-x)}^{2}}+{{5}^{2}}\] ?(ii) On comparing Eqs. (i) and (ii), \[{{12}^{2}}+{{x}^{2}}=(17-{{x}^{2}})+25\] \[\Rightarrow \] \[34x=170\] \[\Rightarrow \] \[x=\frac{170}{34}=5\] \[{{r}^{2}}={{12}^{2}}+{{5}^{2}}=144+25\] \[\Rightarrow \] \[\,{{r}^{2}}=169\] \[\Rightarrow \] \[\,r=13\]You need to login to perform this action.
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