Make sure you know the formula pertaining to the question.
1. c=2(pi)(r)
2. c=2(pi)(d)
r= radius
d= diameter
c= sircumference
So we are given that the circumference of a circle is 12.3pi and the radius is unknown.
So let's plug in the known values
**we use the formula with the radius, becuase we are looking for the radius.
c=2(pi)(r)
12.3(pi)=2(pi)(r)
divide each side by pi
12.3=2(r)
divide each side by 2
r=6.15 in.
X=4
JK=17
JM=19
KM=17
This is the answer
Simplify the exponents
3-2=1 therefore it should be 1/7 the third answer. Hope that helps