Ok so the given is the length of the diameter.
diameter=28 in
so the radius is half the diameter
radius=28/2=14 in
Circumference formula=2 × pi × radius
C=2(pi)(14) - pi can be considered as 3.14 or the value in the calculator
C=28(PI)
C=87.96 in ≈ 88 in
The easiest way is just use the diameter times the pi
Because 2 times the radius is just the diameter
So we can derive that
C= diameter × pi
C=d(pi)
C=28(pi)
C=87.96 in ≈ 88 in
