Posted by alaina on Monday, January 7, 2008 at 4:16pm.
A = pi r^2
A = (22/7)(14)^2 , you do arithmetic
answer in square feet (ft^2)
in the second one r = D/2
so r = (1/2)(10/3) = 5/3 yard
so
A = pi r^2
A = (22/7)(25/9) you do arithmetic
in square yards (yd^2)
The formula for the area of a circle is A = pi*r^2
1.
A = 22/7 * 14 * 14
A = ?
2. In this problem, you need to find the radius -- which is 1/2 of the diameter.
A = 22/7 * 1 2/3 * 1 2/3
A = ?
If you post your answers, we'll be glad to check them.
You were given two questions:
Find the area of each circle use 22/7 for pie.
1. r=14ft
2.d=3 1/3 yd
First of all, it's not pie; it's pi.
Pie is something we eat; pi is an irrational number. The symbol for pi is ð.
The area of a circle formula is:
Area = pi times radius squared, which is written A = ð(r)^2.
We are looking for A, where A represents the area of the circle.
A = ð(14ft)^2
A = (22/7)(14ft)^2
A = 616 ft^2....This is read: "616 square feet." Why square feet? Area is measured in square units.
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For the second question, you were given the diameter as a mixed number.
Your diameter is 3_1/3, which I will write as an improper fraction (10/3).
We need the radius in order to plug it into the area formula as given above.
The radius is 1/2 of the diameter.
So, (10/3) times (1/2) = (5/3)
The fraction (5/3) is our radius here.
We now plug (5/3) for r in the formula for the area of a circle and simplify.
A = ð(r)^2
A = (22/7)(5/3)^2
A = (22/7)(25/9)
A = 550 yards^2...This is read: "550 square yards.
That's it!