There are two kinds of triangular rulers, one is 30 degrees, 60 degrees and 90 degrees, and the other is 45 degrees, 45 degrees and 90 degrees. With these two triangular rulers, you can spell out angles of 30 degrees, 45 degrees, 60 degrees and 90 degrees. So the angles that can't be spelled out with a pair of triangular rulers are 15 degrees and 75 degrees.
The main functions of the triangle ruler include:
1, as a ruler: one side of it is usually a straight line, which can be used to measure and draw a straight line.
2. As an angle measuring tool: the two right-angle sides of a triangular ruler can be used to measure and draw different angles, especially right angles (90 degrees) and other specific angles.
3. As an auxiliary drawing tool: the triangular ruler is often used in conjunction with drawing tools such as pencils and rulers to help draw accurate figures and angles.
The origin of the triangle ruler:
The history of the triangle ruler can be traced back to ancient Greece. In the 6th century BC, the ancient Greek mathematician Pythagoras put forward the famous Pythagorean theorem, which showed that in a right triangle, the square on the right side is equal to the sum of the squares on the other two sides. The discovery and research of this theorem promoted the development of trigonometry.
With the passage of time, people began to use triangle tools to measure and draw angles and graphs. The earliest triangular ruler may be made of wood or ivory, and later it gradually developed into a modern triangular ruler made of plastic or metal. Modern triangular rulers usually have different lengths and angles, which can meet the needs of various measurement and drawing.
The main application of triangular ruler
1, Drawing and Design: Triangular rulers are usually used for drawing, graphic design and building drawing. It can help draw straight lines, angles and various geometric shapes, and ensure the accuracy of drawing.
2. Angle measurement: One side of the triangular ruler can be used to measure and draw different angles, including right angle, acute angle and obtuse angle. This is very important in drawing and measuring.
3. Tabulation, planning and academic education: In the production of tables, charts and plans, draw horizontal and vertical lines and various angles with a triangular ruler to make these documents easier to understand and explain. Students and teachers often use triangular rulers in geometry and mathematics courses to teach and learn the concepts of angles, triangles and geometric shapes.