If the radius of a circle is r cm, what is the area of the circle?

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If the radius of a circle is r cm, what is the area of the circle?

If the radius is increased to 2 r cm, what is the area of the circle?
-Please show your work

2006-09-12 10:41:05 · 4 answers · asked by Chelsey 5 in Education & Reference ➔ Homework Help

4 answers

area = pi r^2

area(r=2r)= pi (2r)^2
area(r=2r)=4pi r^2

2006-09-12 10:42:33 · answer #1 · answered by odu83 7 · 0⤊ 0⤋

ok the formula for Area of circle = pi(r^2)

so, if the radius is r, the area = pi(r^2) ---> the formula!

now, if the radisus is increased to 2r, A = pi(2r)^2 = pi(4r^2)

tada! :)

2006-09-12 17:47:47 · answer #2 · answered by sasmallworld 6 · 0⤊ 0⤋

2 cm times pi or 3.14

2006-09-12 17:47:23 · answer #3 · answered by Pickle 2 · 0⤊ 0⤋

Use pi * r^2

pi r^2
4 * pi * r^2

2006-09-12 18:27:41 · answer #4 · answered by costco.mart 2 · 0⤊ 0⤋