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Question-219879




Question Number 219879 by fantastic last updated on 03/May/25
Answered by A5T last updated on 03/May/25
Let the sides of the rectngle be a and b.  (√((1.5+2)^2 −(a−1.5−2)^2 ))+(√((3+2)^2 −(a−3−2)^2 ))  =b−1.5−3  ⇒(√(7a−a^2 ))+(√(10a−a^2 ))=b−4.5  But a=6⇒(√6)+2(√6)=b−4.5⇒b=((9+6(√6))/2)  ⇒ab=3(9+6(√6))=18(√6)+27
$$\mathrm{Let}\:\mathrm{the}\:\mathrm{sides}\:\mathrm{of}\:\mathrm{the}\:\mathrm{rectngle}\:\mathrm{be}\:\mathrm{a}\:\mathrm{and}\:\mathrm{b}. \\ $$$$\sqrt{\left(\mathrm{1}.\mathrm{5}+\mathrm{2}\right)^{\mathrm{2}} −\left(\mathrm{a}−\mathrm{1}.\mathrm{5}−\mathrm{2}\right)^{\mathrm{2}} }+\sqrt{\left(\mathrm{3}+\mathrm{2}\right)^{\mathrm{2}} −\left(\mathrm{a}−\mathrm{3}−\mathrm{2}\right)^{\mathrm{2}} } \\ $$$$=\mathrm{b}−\mathrm{1}.\mathrm{5}−\mathrm{3} \\ $$$$\Rightarrow\sqrt{\mathrm{7a}−\mathrm{a}^{\mathrm{2}} }+\sqrt{\mathrm{10a}−\mathrm{a}^{\mathrm{2}} }=\mathrm{b}−\mathrm{4}.\mathrm{5} \\ $$$$\mathrm{But}\:\mathrm{a}=\mathrm{6}\Rightarrow\sqrt{\mathrm{6}}+\mathrm{2}\sqrt{\mathrm{6}}=\mathrm{b}−\mathrm{4}.\mathrm{5}\Rightarrow\mathrm{b}=\frac{\mathrm{9}+\mathrm{6}\sqrt{\mathrm{6}}}{\mathrm{2}} \\ $$$$\Rightarrow\mathrm{ab}=\mathrm{3}\left(\mathrm{9}+\mathrm{6}\sqrt{\mathrm{6}}\right)=\mathrm{18}\sqrt{\mathrm{6}}+\mathrm{27} \\ $$

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