The second one that you did
Answer:
10*(9-5)
Step-by-step explanation:
<span>Lets make it clear: You would have a positive answer when the value you are looking for has to be a positive number. On the other hand you would have a positive and a negative answer when you take the square root of something that doesn't have to be positive. it could be either because when a negative number is squared it becomes positive and when a positive number is squared it stays positive as well.</span>
R = 13.1
so
<span>diameter = 13.1 x 2 = 26.2 km
</span>circumference = 2 pi r = 26.2 pi km
or
circumference = 26.2 x 3.14 = 82.27 km
