In this article we present analytical derivation of the Fuss relations for n = 11 (hendecagon) and n = 12 (dodecagon). We base our derivation on the Poncelet closure theorem for bicentric polygons, which states that if a bicentric n-gon exists on two circles then every point on the outer circle is the vertex of same bicentric n-gon. We have used Wolfram Mathematica for the analytical computation. We verified results by comparison with earlier obtained results as well as by numerical calculations.