Answer:
66
Step-by-step explanation:
The diameter of the circle is 21. The formula for circumference is pie*radius*2. We don't have the radius but the diameter is just double the radius so just don't multiply by 2. 21 x 22 = 462. 46s divided by 7 is 66. Enjoy your answer :D
100π
Area of a circle formula: πr²
The radius would be half of 20 m
So the radius, r is 10 m
Plug that in
πr²=π·10²=100π