Answer:
First know the formula for the area of a circle;
A = π
Where 'π' represents pi(3.14 or 22/7), and 'r' stands for the radius being squared.
For the first problem, we can see that 12 is our diameter.
And to find the radius, we need to find 1/2 of the diameter (half of the diameter), so;
D/2 = R
Replace with actual values;
12/2 = 6, 6 is our radius.
Now we plug this into our formula:
A = π
A = 3.14(6^2)
A = 3.14(36)
A = 113.04 centimetres is the area of the circle.
For the second problem, we can see that 18 is our diameter.
And to convert the diameter into the radius, we do what we did to the past problem, find 1/2 of the diameter.
So;
D/2 = R
18/2 = 9, 9 is our radius.
Now we plug this into our formula:
A = π
A = 3.14(9^2)
A = 3.14(81)
A = 254.34 inches is the area for this circle.
For the third problem, we can see that our radius is already given, 5.
So now we just simply and easily plug this into our formula;
A = π
A = 3.14(5^2)
A = 3.14(25)
A = 78.5 meters is the area for this circle.