Answer:
area of a circle formula:
radius squared x pi(3.14 or 22/7 most likely whatever they tell you to use in pi)
Circumference formula:
2 x pi(3.14 or 22/7 most likely whatever they tell you to use in pi) x r(radius, if they dont give you the radius but just your diameter for either circumference of area just do half of the diameter shown)
Step-by-step explanation:
First problem:
In this case,
7 is your radius!
7 x 2 x 3.14 (circumference) = 43.96
now area: 7^2 = 49
49 x 3.14 = 153.86
Now time for the other problem:
half of 30 is 15!
15 x 3.14 x 2 (circumference) = 94.2
Area of the circle:
15^2 = 225
225 x 3.14 = 706.5
