If the diameter of a circle is 20cm, what is the area? ?

Question

can someone please show me how to do ir or have a web page that shows me how to get the answer because people are giving me different formulas

Answer 1

Check out this website

http://www.ih.k12.oh.us/MSDunlap/Geometr...

Answer 2

area = pi r^2

radius = 1/2 of diameter

radius = 10cm

10^2 pi = 100 pi

100pi square centimeters is most accurate and is an exact answer but rounded the number is about 314.16 square centimeters

As an added note, pi x diameter or 2 pi x radius = circumference

Answer 3

The way to get the area of the circle is: the radius squared, times pi.

If the diameter of the circle is 20, then the radius is 10.

So the area is 10 squared times pi

10 squared is 100, so the area is 100 times pi

100 times pi is approximately 314.15926

so there's your answer!

Answer 4

The area of a circle is pi times the radius squared. The radius is half of the diameter, so it would be 10. 10 squared is 100, so it is 100 pi or 100 times pi. Hope this helped.

Answer 5

the area formula of a circle is area = pi r^2

r is the radius..

if the diameter is 20 then the radius is half that and is 10

so you plug it in

A=pi10^2

A=314.1592654

Answer 6

area = pi * r^2   or  area = pi * (d/2)^2

where r is the radius and d is the diameter

so the area is

pi * (10 cm)^2 = pi * 100 cm^2

area of the circle is 100* pi cm^2

Answer 7

pieD square divide by 2 :P Hopes I helped! Thats the formula to get the area.

Answer 8

20 x 3.14    this is the correct formula: (A)= Dx3.14  or 3.14 xradius sqaured

Answer 9

To find the area of a circle, you multiply pi (3.14) by the square of the radius. The radius is half of the diameter, which means the radius of the circle is 10cm. To square a number means to multiply it by itself. So, 3.14x10x10 = 314cm squared. 314cm squared is the area of the circle.

Answer 10

the formula is pi times the diameter

so the math would be 20 times 3.1416 which equals 62.832 cm

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Answer 11

Well, the formula to get the area of a circle is pr^2. p = 3.14, r = radius. Since you have the diameter here, you can get the radius by dividing it in two. This is just to avoid the confusion.

So you have a diameter of 20cm. That makes your radius = 10cm. You can now use the formula:

A = pr^2

A = (3.14)10^2

A = (3.14)100

A = 314 square centimeters

Answer 12

the formula to find the area of a circle is A = [Pi]r2 where "r" is the radius and pi=3.14 (or 22 divided by 7 to be more exact)

the radius is half of the diameter

so half of 20 is 10

then you take 10 and you square it

10x10= 100

then multiply 100 by 3.14 and you'll have you you're answer

Answer 13

1/2 diameter x pie ( 3.14) = area

Answer 14

The area of the circle is determined by this formula : 2 pi r^2

The diameter is 2r, so divide 20 by 2

Witch gets you 10.

Now substitute 10 in place of the r

Answer 15

Im pretty sure the formula is pie R Squared so the answer would be 100 times pie