An instrument for marking out or measuring angles, typically in the form of a flat semicircle marked with degrees along the curved edge.

An instrument for measuring or marking off angles consisting of two arms pivoted about a common centre, each with sights, and a protractor or…

An instrument used for measuring angles.

A name given to various trigonometrical instruments.

Designating an instrument for measuring angles in which accuracy is obtained by observing and measuring an angle repeatedly round a graduated circle…

A device for measuring external angles.

a device used to set out or measure angles accurately, in which one end of a bar of known length is raised on gauge blocks.