Question

In Fig. 7, a small indoor green house is made entirely of glass panes (including base) held together with tape. It is 30 cm long, 25 cm wide and 25 cm high. What is the area of the glass? How much tape is required for all the 12 edges?

Answer 1

$$\begin{gathered} \mathrm{We}\mathrm{have}, \\ \mathrm{Length}\mathrm{of}\mathrm{the}\mathrm{indoor}\mathrm{green}\mathrm{house},l=30\mathrm{cm}, \\ \mathrm{Breadth}\mathrm{of}\mathrm{the}\mathrm{incdoor}\mathrm{green}\mathrm{house},b=25\mathrm{cm}\mathrm{and} \\ \mathrm{Height}\mathrm{of}\mathrm{the}\mathrm{indoor}\mathrm{green}\mathrm{house},h=25\mathrm{cm} \\ \mathrm{Now}, \\ \mathrm{Area}\mathrm{of}\mathrm{the}\mathrm{glass}=\mathrm{Total}\mathrm{surface}\mathrm{area}\mathrm{of}\mathrm{the}\mathrm{cuboid} \\ =2\left(lb+bh+hl\right) \\ =2\left(30\times 25+25\times 25+25\times 30\right) \\ =2\left(750+625+750\right) \\ =2\times 2125 \\ =4250{\mathrm{cm}}^2 \\ \mathrm{Also}, \\ \mathrm{The}\mathrm{length}\mathrm{of}\mathrm{the}\mathrm{tape}\mathrm{required}=4\left(l+b+h\right) \\ =4\left(30+25+25\right) \\ =4\times 80 \\ =320\mathrm{cm} \end{gathered}$$