Question: 3-D Cube in Maple

Hello,

I am trying to make a three dimensional cube in maple by using matrices. I also have to make it rotate about the x,y,z axes, project it with three different origins, and translate it (I'm assuming this means translate it across an axis?). I have already made the cube, but when I try to rotate it across one of the axes by multiplying my matrix by one of the rotation matrices (this is what I put un maple: P1:= matrix([[1,0,0,0],[0,cos(theta),-sin(theta),0],[0,sin(theta),cos(theta),0],[0,0,0,1])) My matrix for the cube has four rows and eight collumns, so I assume I have to make the rotatin matrix have four collumns so they can multiply together. So after I multiply these, my 3-D cube rotates about the x-axis, but it is no longer 3-D it is just a straight line. 

I hope this is enough information, and thank you in advance!!