Question

A small indoor greenhouse (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

Given:

$\Rightarrow$$l=30,b=25,h=25$

(i) Total S.A of green house

$=2(lb+bh+lb)$
$=2(30\times 25+30\times 25+25\times 25)$
$=4250$ cm${}^2$

(ii) For $12$ edges: Total length

$=4l+4b+4h$
$=4(30+25+25)$
$=320$ cm