1. The problem statement, all variables and given/known data Find out the degrees of freedom of a block of wood sliding on a horizontal plane. 2. Relevant equations DoF=Nn-k N=no. of dimensions. n=no. of particles.k= no. of constraints. 3. The attempt at a solution I am considering the block of wood as a rigid body made of n no. of particles. But it will move with respect to a center of mass. I will need 3 points on the body to define the CM. As the body is constrained to move on a plane each of these 3 points can be denoted with 2 coordinate points. Each of these 3 points has fixed distance from each other so there will be 3 constraints if these points are non collinear. So i think the answer should be 3×2-3=3. Are my deductions correct??