Question

​Area of a trapezium is 110 metre square. height is 11 metre and one of the parallel side is 7cm.find the other?

Answer 1

$$\begin{gathered} \mathrm{Let}\mathrm{a}\mathrm{nd}\mathrm{be}\mathrm{the}\mathrm{parallel}\mathrm{sides}\mathrm{of}\mathrm{the}\mathrm{trapezium}\mathrm{and}\mathrm{h}\mathrm{be}\mathrm{its}\mathrm{height}. \\ \mathrm{Now},\mathrm{a}=7\mathrm{cm};\mathrm{h}=11\mathrm{cm};\mathrm{area}=110{\mathrm{cm}}^2;\mathrm{b}=? \\ \mathrm{Now},\mathrm{area}=\frac{1}{2}\left(\mathrm{a}+\mathrm{b}\right)\times \mathrm{h} \\ \Rightarrow 110=\frac{1}{2}\left(7+\mathrm{b}\right)\times 11 \\ \Rightarrow 7+\mathrm{b}=20 \\ \Rightarrow \mathrm{b}=20-7=13\mathrm{cm} \end{gathered}$$