Abstract: A drawing triangle is disclosed having 30-, 45-, and 105-degree angles. A perpendicular starting from the vertex of the obtuse angle meets the base at a right angle, from the point where said perpendicular meets said base a set of three reference lines extends making angles of 7 degrees, 30 degrees, and 42 degrees with the base line respectively. Inside the edges of the drawing triangle a set of three base lines each parallel to its corresponding edge are further provided. Between said inner base lines and the edges of the triangle, sets of broken parallel lines are provided which can be used to draw parallel lines with accuracy. Sets of scales are also provided along said perpendicular and the base edge of the drawing triangle.