Question

A closed cylindrical tank of radius 7m and height 3m is made from a sheet of metal . how much sheet of metal is requried?​

Answer 1

Answer:

when you need to find material then you need to find surface area

Answer 2

Area of sheet(open from upper side)= 606m^2

Area of sheet(open from upper side)= 606m^2Area of sheet(closed from upper side) = 770m^2

Step-by-step explanation:

Curved surface area of tank =

$\pi {r}^{2} h$

=

$\frac{22}{7} \times 7 \times 7 \times 3$

=

$22 \times 7 \times 3$

=

$462 {m}^{2}$

Now,if the tank is open from upper side:

Area of sheet used =

$462 + \pi {r}^{2}$

=

$462 + \frac{22}{7 } \times 7 \times 7$

=

$462 \: + 154$

= 616 m^2

If the tank is closed from upper side:

Area of sheet used =

$462 + 2\pi {r}^{2}$

= 462 + 2×154

= 462 + 308

= 770 m^2