a protractor is used for measuring the angles of a triangular object
triangle is geometric_figure. triangle is instrument. triangle is not tool. triangle is figure. viscometer is measuring_instrument. protractor is drafting_instrument. triangle is geometric_figure_with_three_sides. vertical_protrusion_topographical is not convex_tangible_object. triangle is tool. vertical_protrusion_topographical is convex_tangible_object.