Answer:
The amount of steel used = 94.38
Step-by-step explanation:
Height of the tank = 4.5 m.
Diameter of the tank = 4.2 m.
But,
radius =
=
radius = 2.1 m
Total surface area of a cylinder = 2rh + 2
= 2r(r + h)
= 2 x x 2.1 (2.1 + 4.5)
= 44 x 0.3 (6.6)
= 87.12
Total surface area of a cylinder = 87.12
Since of the steel was wasted, then;
x 87.12 = 7.26
Actual area of steel sheet used = 87.12 + 7.26
= 94.38
Thus, 94.38 of steel was used in making the tank.