I would like to order a comfort mat for the floor of a small kitchen. The company can make it to order but I have to provide exact dimensions. This is harder that it sounds though as the floor space is best described as an irregular pentagon with 2 non-right angles. What tools or methods could be used to easily and accurately measure the surface so that I can provide an accurate sketch to the manufacturer? I haven't used a protractor since high-school but I don't see how that could be used to measure a wall angle.
If they'll accept a full-size model, use the technique for making a template for cutting vinyl flooring to the right size and shape (taken from another answer of mine):
If they want a smaller-scale model, use a T-bevel or angle finder to measure the angles in the corners and careful measurement to get the lengths of the walls.
To verify your accuracy, measure the diagonals going across the room and compare to your scale model.