Let
C---------> the circumference of a circle
D---------> diameter of a circle
r----------> radius of a circle
we know that
C=2*pi*r
D=2*r
so
C=D*pi-------------> pi=C/D
<span>Pi is defined as the ratio of the circumference of a circle to the diameter of that Circle
when you multiply the diameter in both numerator and denominator
pi*D=(C/D)*D------> pi*D=C
and the diameter is two times the radius
so
D=2*r
C=pi*D------> C=pi*(2*r)-----> C=2*pi*r
therefore
the answer is the option D
</span>Two times r equals the diameter of the circle. Pi equals the circumference divided by the diameter. When you multiply, the diameter is in both the numerator and the denominator, which cancels out, leaving the circumference
What they said at the top
Answer:
Step-by-step explanation:
You would write AB with a horizontal line segment over the letters A and B
So you would write this 
If you cannot draw that on your computer, then I would stick to saying "segment AB".