Answer
$5.15$ X $10^{14}$ $m^{2}$
Work Step by Step
Now,Surface area , $area=4\pi r^{2}$
Here, radius, $r=6.4$ X $10^{6}$ $m$
Thus, $area=4$ X $\pi$ X $(6.4$ X $10^{6})^{2}$ $m^{2}$
This becomes : $area=4$ X $\pi$ X $40.96$ X $10^{12}$ $m^{2}$
$area$ $\approx$ $514.457$ X $10^{12}$ $m^{2}$
To represent the area in scientific notation,we shift the decimal point by $2$ places and hence multiply the area by $10^{2}$
Thus, $area$ $\approx$ $5.14457$ X $10^{14}$ $m^{2}$
You can round off the number if required.
Rounding off, $area\approx$ $5.15$ X $10^{14}$ $m^{2}$
