1.
radius= 10
diameter= 20
circumference formula: C = 2•pi•r
circumference: 62.8
area formula: A = pi•r^2
area: 314
2.
radius= 6
diameter= 12
circumference formula: C = 2•pi•r
circumference: 37.68
area formula A = pi•r^2
area: 113.04
hope this helps!