Answer:
Step-by-step explanation:
You'll need to learn the formula for the circumference of a circle. If the radius is r, the circumference C is C = 2πr. It appears that your teacher is using pi for the exact circumference and 3.14 for the approximate circumference.
The radius of the first circle is 5 in. Thus, the exact circumference is
C = 2πr = 2π(5 in) = 10π in, and the approximate circumference is
C = 2(3.14)(5 in) = 31.4 in
