If d = 20 and C = 20π

If d = 26 and C = 26π

If r = 12 and C = π

If r = 18 and C = 14π

If r = 6 and C = 12π

If r = 50 and C = 100π

^Matches w

then d = 1

then d = 100

then d = 12

then d = 14

then r = 10

then r = 13

What goes w what!

If d = 20 and C = 20π, then r = 10.

If d = 26 and C = 26π, then r = 13.

If r = 1/2 and C = π, then d = 1.

If r = 7 and C = 14π, then d = 14.

If r = 6 and C = 12π, then d = 12.

If r = 50 and C = 100π, then d = 100.

*Note, r = 1/2*d or d=2*r