How fast (in `m^2//s`) is area swept out by
(a) the radius from sun to earth ?

Explanation

The rate, at which the area is swept out by the radius from the sun to the earth ,
`(dA)/(dt)=(pir^2)/(T)`
Here, `r=1.496xx10^(11)m`,
`T=365 days = 365 xx24xx60xx60s`
`therefore (dA)/(dt)=(pixx(1.496xx10^(11))^2)/(365xx24xx60xx60)=2.23xx10^(15)m^2*s^(-1)`