Different measuring tools in technical drafting

A ruler, sometimes called a rule, line gauge, or scale, is a device used in geometry and technical drawing, as well as the engineering and construction industries, to measure distances or draw straight

A triangle is a drafting tool used to draw accurate parallel lines, vertical lines, and other angled lines. Generally, two right-angled triangular pieces of differing angles form one set. On one piece, the angles are 90°, 60°, and 30°; on the other, an isosceles triangle is formed with angles 90°, 45°, and, 45°. One is scaled; the other is not. Some transparent triangles made from plastic and acrylic feature grids.

A T-square is a technical drawing instrument used by draftsmen primarily as a guide for drawing horizontal lines on a drafting table. It may also guide a set square to draw vertical or diagonal lines.

A protractor is a measuring instrument, typically made of transparent plastic or glass, for measuring angles. Some protractors are simple half-discs or full circles. More advanced protractors, such as the bevel protractor, have one or two swinging arms, which can be used to help measure the angle.

A French curve is a template usually made from metal, wood or plastic composed of many different segments of the Euler spiral. It is used in manual drafting and in fashion design to draw smooth curves of varying radii.

A triangular scale is a ruler that has a 3-lobed cross-section with 6 different types of scales on the edges (2 on each face) used for measuring and preparing scale drawings such as blueprints and maps.

A set square or triangle is an object used in engineering and technical drawing, with the aim of providing a straightedge at a right angle or other particular planar angle to a baseline. The simplest form of set square is a triangular piece of transparent plastic with the centre removed.