Use a plate protractor to lay out the angle. The bevel protractor from the combination set is also a suitable tool for this application. Be sure that the protractor is set to the correct angle. The edge of the protractor blade must be set exactly at the 5-in. Mark. The layout of the 31-degree angle establishes its complement of 59 degree on the drill gage. The correct included angle for general-purpose drill points will be 118 degree, or twice 59 degree. The corner radius is 1/2 in. Establish this dimension using the square and rule.