Goniometers
Angle meters are tools used to measure angles. They include combination protractor-rulers and slant rules with a dial. With a protractor-ruler, the protractor and rod are placed against the object to measure angle, and many of those tools come in stainless steel or aluminum. Those with a silver finish for have minimal gloss, making the scale easier to read. Some models have a digital LCD. Slant rules are tools to measure the angle of a slope, and they are used in work such as plumbing, drain construction, and steel-frame structure construction. Zero can be set at an arbitrary position with digital angle meters, and they are used when measuring the angle of machines, dies, jigs, tools, and the like and when assembling.