A set square (or drafting triangle) is a precision right-angled triangular instrument used in technical drawing, engineering design, and math classes to draw perfect vertical lines, perpendiculars, and specific angular projections.
- They are almost always sold in matching pairs containing two distinct geometric shapes to give you immediate access to a wide range of standard angles.
- The Standard Set Square PairA professional set square kit includes two distinct triangular pieces that work together to map out critical angles:
- The 45° Set Square: An isosceles right-angled triangle. It features one 90° angle and two 45° angles. It is primarily used for drawing standard 45-degree cross-hatching, square layouts, and mapping half-perpendiculars.
- The 30°/60° Set Square: A scalene right-angled triangle. It features a 90° angle, a sharp 30° angle, and a 60° angle. This piece is essential for drawing isometric projections (which rely on a 30-degree baseline layout).
