First since you know the radius:3 the perimeter of a full circle would be
2pi x 3 = 6 pi. But since it's only half it would be 3 pi.
6+3+3+3pi gets you 12+3 pi
ok so lets say that you have a pizza cutted out in 5 sections and want to pick up only a certain piece, let's say pepperoni. If you took a piece at random, the chances of getting that certain piece of pepperoni in 60 spins is: 12 / 60
30-24=6 6/30=0.2
0.2x100=20
20%
