Question:
Find the capacity of a closed rectangular cistern whose length is 8 m, breadth 6 m and depth 2.5 m. Also, find the area of the iron sheet required to make the cistern.
Solution:
Length of the cistern, l = 8 m
Breadth of the cistern, b = 6 m
Height (or depth) of the cistern, h = 2.5 m
∴ Capacity of the cistern
= Volume of the cistern
= l × b × h
= 8 × 6 × 2.5
= 120 m3
Also,
Area of the iron sheet required to make the cistern
= Total surface area of the cistern
= 2(lb + bh + hl)
= 2(8 × 6 + 6 × 2.5 + 2.5 × 8)
= 2 × 83
= 166 m2