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:
C: 
Step-by-step explanation:
Since a = 
:
Since n = 4 :
They need to have common denomenators so change the fractions to 12/15 - 5/15 which is 7/15.
2(b + 3c) → We first need to simplify this.
Simplify.
2b + 6c
1st Option :
3(b + 2c)
Simplify.
3b + 6c
This is INCORRECT, as it is not equal to 2b + 6c.
2nd Option :
(b + 3c) + (b + 3c)
Simplify.
2b + 6c
This is CORRECT because 2b+6c = 2b+6c
(b + 3c) + (b + 3c) → Answer
~Hope I helped!~
To find<span> the </span>cube root of a number<span>, you want to </span>find <span>some </span>number<span> that when multiplied by itself twice gives you the original </span>number<span>. In other words, to </span>find <span>the </span>cube root<span> of 8, you want to </span>find<span> the </span>number<span> that when multiplied by itself twice gives you 8. The </span>cube root<span> of 8, then, is 2, because 2 × 2 × 2 = 8.</span>
