Circumference of a circle - derivation
This page describes how to derive the formula for the circumference of a circle.
Recall that the definition of pi (π) is the circumference c of any circle divided by its diameter d. Put as an equation, pi is defined as
π
=
c
d
Rearranging this to solve for c we get
c
=
π
d
The diameter of a circle is twice its radius, so substituting 2r for d
c
=
2
π
r
If you know the area
Recall that the area of a circle is given by
area
=
π
r
2
Solving this for r
r
2
=
a
π
So
r
=
√
a
π
The circumference c of a circle is
c
=
2
π
r
Answer:
The Answer is: 75.
Step-by-step explanation:
Set up the equation:
45 / 600 = y / 1000
600y = 45 * 1000
600y = 45000
y = 45,000 / 600 = 75.
Answer:
A 20/28
Step-by-step explanation:
10 percent of 11.50 is 1.15. Subtract that from 11.50 and you would get 10.35. The sale price would be $10.35
Hi there!
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I believe your answer is:
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Here’s why:
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Hope this helps you. I apologize if it’s incorrect.
