Question

A closed tin of milk has diameter 10cm and height 16cm. Find the total surface of the tin.(take π to be 22/7)

Answer 1

2πr(h+r)
2π×10(16+10)
=2×22/7×10(26)
=44×260/7
=11440/7
=1634.3

Answer 2

d = diameter

r = radius

Surface area:

A = 2 area of circles + 1 area of rectangle = 2 r² π + 2 r π h = 2 r π ( r + h )

r = d / 2 = 10 / 2 = 5 cm

A = 2 ∙ 5 ∙ 22 / 7 ∙ ( 5 + 16 ) = 2 ∙ 5 ∙ 22 ∙ 21 / 7 = 660 cm²

OR

A = 2 area of circles + 1 area of rectangle = 2 d² π / 4 + d π h =

d² π / 2 + d π h = d π ( d / 2 + h )

10 ∙ ( 22 / 7 ) ∙ ( 10 / 2 + 16 ) = 220 / 7 ∙ ( 5 + 16 ) =

220 ∙ 21 / 7 = 4620 / 7 = 660 cm²

Answer 3

As = 2(pi*r^2)+2pi*r*h = 2(3.14*5^2) + 6.28*5*16 = 659.5 cm^2.