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.
`therefore` Area is 56.5 `m^(2)`.