Yellow
Green
Blue
Red
Magenta
Remove
Kathy models the problem using circle pieces. Then she solves the problem in two different ways, one like the method Romesh used and another using her own method.
Romesh's way
Replace the yellow piece and the orange piece with black pieces, since black is the only color piece that fits on both of the other pieces evenly.
Kathy's way
Looking at the model, the answer is a little more than 
. I try different pieces and find that it is larger than by one black piece. A black piece is 
.
