Question

A small indoor green house (herbarium) is made entirely of glass panes (including base) held together with tape. It is $30cm$ long, $25cm$ wide and $25cm$ high.
(i) What is the area of the glass?
(ii) How much of tape is needed for all the$12$ edges?

Answer 1

$\left(i\right)$ Area of glass = Total surface area (T.S.A) of the room

$\Rightarrow T.S.A=2(lb+bh+lh)$

$\Rightarrow T.S.A=2\left(\right(30\times 25)+(25\times 25)+(25\times 30\left)\right)$

$\Rightarrow T.S.A=2(750+625+750)$

$\Rightarrow T.S.A=4250c{m}^2$

$\Rightarrow Areaofglass=4250c{m}^2$

$\left(ii\right)$ Total length of edges$=4(l+b+h)$

$\Rightarrow 4(30+25+25)=320cm$

therefore, $320cm$ of tape is required