To figure a radius corner use a piece of paper and run one edge along A to Point B and the other edge along C to Point B. B will be the corner of the paper. Now simply mark the paper where the radius begins and measure to the corner of the paper. This dimension is the corner radius dimension.

Another very simple way, but not as accurate, is to take a dime, nickel or quarter and place it on the corner. If one of the coins matches up then that is the radius. For instance, if a dime has the radius you need, it is called a “dime radius”.