Answer:
4.5×10^17 m²
Step-by-step explanation:
The radius is half the diameter, so we can make the substitution r=d/2 into the formula to get ...
A = 4πr² = 4π(d/2)² = πd²
Filling in the given values and doing the arithmetic gives ...
A = 3.14×(3.8×10^8 m)² = 45.3416×10^16 m²
A ≈ 4.5×10^17 m²
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We round to 2 significant digits because that is the precision of the given diameter.
