An angle gauge and method of use. The angle gauge has a housing with a housing probe wall and a housing foot defining a gauge angle. A pair of probes extends from the housing probe wall. A light and a battery are electrically connected in series between the probes. A pre-determined angle between an object and a flat surface can be gauged by placing the angle gauge with its housing foot flat on the flat surface, and then sliding the angle gauge across the flat surface until at least one probe is in electrical contact with the object, and then adjusting the angle of the object relative to the flat surface until both probes are in contact with the object, thereby illuminating the light. A conductor may be attached to non-conducting objects. A method of calibration is disclosed using a calibrated angle.