Oh yes... Wonderful Proportions. There are ways to do proportions but this is how I learned how to do them :
PART %
=
WHOLE 100 That is the formula. I'm not sure of an example but I hope it helps
Answer:
yes it is right no one is mistake
Well if d= 20
d=2r
so 20 = 2r
r=10
is that what you wanted, or does this have to do with a circle
Amy: 12 or 30
Sue: 0.34
Kit: 9/21
Kit is the better hitter.
Hope this helps :^)
