We can list all angles that can be drawn directly by a pair of triangular rulers and calculate the total. A pair of triangular rulers mainly includes four angles of 30 degrees, 45 degrees, 60 degrees and 90 degrees. We can draw the following angles directly: 30 degrees, 45 degrees, 60 degrees, 90 degrees, 15 degrees, 30 degrees, 75 degrees, 105 degrees, 120 degrees, 135 degrees,10.

Function of triangular ruler

1, triangular ruler plays an important role in mathematics teaching. When learning geometric figures, the triangular ruler can help students better understand the concepts of right angle, acute angle and obtuse angle. Using the triangular ruler, students can intuitively observe the relationship between different angles, thus deepening their understanding of the nature of angles. In addition, the triangular ruler can also be used to measure the length of line segments to help students master the measurement skills.

2. Triangular ruler is widely used in engineering field. In building engineering, architects need to accurately calculate the angle and size of the building to ensure the stability and aesthetics of the building. Triangular ruler can help architects to measure angles quickly and accurately and improve design efficiency. At the same time, the triangular ruler can also be used to draw plans, elevations and other drawings, providing a basis for construction.

3. In the field of mechanical manufacturing, the triangular ruler also plays an important role. Mechanical engineers need to manufacture various parts according to design requirements, and these parts often need accurate angles and dimensions. By using the triangular ruler, engineers can ensure the accuracy of parts and improve the quality of products. In addition, the triangle ruler can also be used to detect the size and shape of parts to ensure that they meet the design requirements.

4. In art design, the triangular ruler also has certain application value. Artists can draw precise lines and patterns with a triangular ruler to improve the aesthetic feeling of their works. At the same time, the triangular ruler can also be used to measure the proportion and position of objects, helping artists to better grasp the overall effect of their works.

Triangular ruler is also widely used in geographical mapping, navigation, astronomy and other fields. In these fields, trigonometry can help professionals accurately measure the angle and distance of the earth's surface and provide important data for scientific research.