The Pythagorean theorem \({x}^{2}+{y}^{2}={z}^{2}\) is usually stated over the integers \(Z\) , a subring of the reals \(R\) , and it holds true for infinitely many solutions. We explore the theorem over subrings of other number spaces, such as \(H\) (quaternions) and \(O\) (octonions). We present several results mainly for L (Lipschitz quaternions) and provide a geometric interpretation of the theorem in the subring \(L\) . Some results for the corresponding subring G of O are also presented. Finally, we also present some results for the rings \(H/{Z}_{p}\) and \(O/{Z}_{p}\) .