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
20+(-3.05)+(-9.8)=20-3.05-9.8=7.15
Here let us first write the value of each number:
6 thousands means 6*1000=6000.
9 hundreds means 9*100=900.
12 tens means 12*10 =120
10 ones means 10*1 =10
3 tenths means 3/10 =0.3
Now we just have to add all these values to get the final number.
adding 6000 + 900 +120 +10 +0.3 = 7030.3
So the final number is 7030.3
Answer:
2197 cubic centimeters
Step-by-step explanation:
13^3=2197
