It is pretty much all the way
13.99 kilometers is the diameter.
Divide the circumference (43.96) by 2(pi), which should give you a radius of 6.99. You should then proceed to multiplying that by 2, since radius is half of the diameter, giving you 13.99.
7+3=10 10+4=14 14+5=19
The surface area is 19
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