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:
0.54
Step-by-step explanation:
You take 54 and divide it by 100
54/100 =0.54
Hope this helps!!
Answer:
625.25
Step-by-step explanation:
the answer is 625.25
If I remember right the answer is c
<h2>
Answer</h2>
After the dilation
around the center of dilation (2, -2), our triangle will have coordinates:



<h2>Explanation</h2>
First, we are going to translate the center of dilation to the origin. Since the center of dilation is (2, -2) we need to move two units to the left (-2) and two units up (2) to get to the origin. Therefore, our first partial rule will be:
→
Next, we are going to perform our dilation, so we are going to multiply our resulting point by the dilation factor
. Therefore our second partial rule will be:
→
→
Now, the only thing left to create our actual rule is going back from the origin to the original center of dilation, so we need to move two units to the right (2) and two units down (-2)
→
→
Now that we have our rule, we just need to apply it to each point of our triangle to perform the required dilation:













Now we can finally draw our triangle: