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 edge

Explanation

The indoor greenhouse is in the shape of a cuboid having length = 35 cm, breadth = 30 cm and height = 25 cm
(i) Area of the glass
= the total surface area of the cuboid
`= 2(lb + bh + lh)`
`= 2 xx [(35 xx 30) + (30 xx 25) + (35 xx 25)] cm^(2)`
`= (2 (1050 + 750 + 875) cm^(2) = (2 xx 2675) cm^(2) = 5350 cm^(2)`
(ii) Length of tape needed for all 12 edges
= (perimeter of top) + (perimeter of bottom) + (4 vertical edges)
`= {2(l +b) + 2(l +b) + 4h} = 4 (l + b + h)`
`= 4 (35 + 30 + 25) cm = 360 cm = 3 cm 60 cm`