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
I am slightly confused. What exactly is the question?
Answer:
3
1
2
Step-by-step explanation:
Math simplification
Answer:
345.
Step-by-step explanation:
Just divide 407.10 by 1.18 and you'll get your answer.
Answer:
19.15
Step-by-step explanation:
so find the circumference of the circle using c=2*pi*r it's like 18.849. then find the perimeter of the box so p=2l+2w and it's like 38. so subtract the circle circumference from 38 so 38-18.849=19.15
