How do you keep warm in cold room?

This joke is a play on words involving a double meaning of “degrees.” In one sense, degrees measure temperature, and in another, they measure angles. The humor comes from the fact that a corner in a room is part of a right angle, which is 90 degrees. The joke suggests that by going to the corner, you would be warmer because of the “90 degrees,” even though this is a geometric term and has nothing to do with temperature. It’s funny because it takes a fact that is true in geometry and applies it incorrectly to a situation involving temperature, leading to a humorous and absurd conclusion.