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:
32
Step-by-step explanation:
The number that take algebra i includes those who take both subjects, as does the number taking algebra ii. Then the number taking algebra i alone is ...
18 -10 = 8 . . . . . take only algebra i
So the number taking any kind of algebra is ...
20 + 8 = 28
and the number not taking either subject is ...
60 -28 = 32 . . . not taking either subject
No 15/3 does not belong to the set of numbers
Answer:
.
Step-by-step explanation:
The given equation is
Using distributive property, we get
Isolate variable terms.
Divide both sides by -0.35.
Therefore, .
