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

Given :
Length (l) of greenhouse = 30 cm
Breadth (b) of greenhouse = 25 cm
Height (h) of greenhouse = 25 cm

We know that,
Total surface area of greenhouse
=2 [lb + lh + bh]
= [2 (30 x 25 + 30 x 25 + 25 x 25)] \({cm}^2\)
= [2(750 + 750 + 625)] \({cm}^2\)
= [2 x 2125] \({cm}^2\)
= 4250 \({cm}^2\)

Therefore, the area of glass is 4250 \({cm}^2\).


It can be observed that tape is required alongside AD, OC, CD, DA, EF, FG, GH, HE, AH, BE, DG, and CF.

We have, Total length of tape
= 4(l+ b + h)
= [4(30 + 25 + 25)] cm
= 320 cm

Therefore, 320 cm tape is required for all the 12 edges.