Answer:
r=4.5, d=9
Explanation:
So, lets go over two things.
#1 - What is Diamater?
Diamater is the distance from one side of a circle to the other.
#2 - What is radius?
Radius is the distance from any side of the circle, to the middle. This is half of the diamater.
In this case, the distance from one side of the circle to the other is 9in.
So the diamater must be 9.
d=9 in
Since we know the radius is half of the diamater, radius is:
9/2
=
4.5 in
So our radius must be 4.5.
r=4.5
This looks like the top answer.
Hope this helps! :D