The diameter of a sphere is `4.24` m . Calculate its surface area with due regard to significant figures .

Explanation

Diameter d = 4.24 m
Radius `r=(d)/(2)=(4.24)/(2) = 2.12`
`"surface area of sphere" = 4pir^(2)`
`= 4 xx 3.1428 xx 2.12 xx 2.12`
In the above multiplication 2.12 has 3 significant figures.
Hence 3.1428 is rounded off to have 3 + 1 = 4 significant figures. It becomes 3.143.
`"Surface area" = 4 xx 3.143 xx 2.12 xx 2.12`
= 56.50
56.50 this to be rounded off to have 3 significant figures.
`:.` Area is `56.5 m^(2)`