Answer:
Circumference: 65.9734 inches
Area: 346.361 square inches
Explanation:
If the diameter is 21 inches, we know the radius, r, is 10.5 inches because the radius measure is half of the diameter.
Circumference Formula: 2πr
=2π(10.5)
=65.9734 inches
Area formula: π
π(10.5)^2
= 346.361 square inches