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 `= 4pi r^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 `56.5m^2`