Q=4πP\mathrm{Q}=4 \pi PQ=4πP
Q=4P\mathrm{Q}=4\mathrm{P}Q=4P
Q=πP4\mathrm{Q}=\dfrac{\pi P}{4}Q=4πP
Q=πP\mathrm{Q}=\pi \mathrm{P}Q=πP