???????????? REGULAR POLYGON ?????????
8-side regular polygon... if eech side=1, hite=2.414214
wide=hite
kalkulate radius av serkel INSIDE the polygon=(sine/2)*tan(beta)
weer alfa=360 deg/n (number-sides)
& beta=(180-alfa)/2
for 8 sides, alfa=45 deg, beta=67.5deg & tan(beta)=2.4142135624
so if hite=10, side=10/2.414214=4.142134873