The planet Mars could be a future destination for the U. S. space program. Assume that Mars is a perfect sphere. Its surface area is about 145 million square kilometers. What is the radius of Mars at its equator? Round to the hundreds place.

||| Answer choices:

A) 4,500 km

B) 2,200 km

C) 5,000 km

D) 3,400 km |||

Surface area of a sphere is 4 times pi timers radius^2

aprox pi=3.14

so surface area=145,000,000

145,000,000=4 times 3.14 times rdaius^2

145,000,000=12.56 times radius^2

divide both sdies by 12.56

11544585.987=r^2

square root both sides

3397.73=radius

round to the hundreds

3397 rounded to the hundreds

3400

the answer is D 3,4000 km