In OpenGL I have to rotate a cube (and translate it) so that it looks like in these two images. ![cubes](https://i.imgur.com/eehEX.png)

Without any transformations only the front facing red face is visible. I just don't understand how I can rotate it (so that the top and right sides are visible like in the images) and keep the red face perfectly square.

I've thought about translating it to the bottom left, but that only moves the red square around, it doesn't make the other faces visible.

I'm using `glFrustum(-20, 20, -20, 20, -1, -10);`