If the plural of octopus is octoπ, that means that 2 x octopus = 8 x π, ergo one octopus = 4π. From this we get that the circumference of an octopus' head is 2πr, ergo 1/2 octopus x r, and as such we can conclude that the radius of an octopus' head is equal to one-half its owner.