Answer:
1. 12 cm.
2. 6.5 cm
3.
a. 87.92 cm
b. 615.44 cm
Step-by-step explanation:
1. just multiply the radius by its self to get the diameter
2. divide the diameter to two to get it's radius
3.
a. the formula for circumference is C=2πr
b. the formula for area is A=πr²