Geodreieck – a drawing tool with a past

Generations of people were born from triangle ruler accompanied by the school time. But hardly anyone thinks that similar drawing instruments were used in ancient Egypt in the third millennium BC. The Egyptians used so-called construction Remen to make the necessary field surveys of the annual Nile floods. Of course, the shapes have of course changed and simplified over the centuries, but the purpose of the geodesic triangle is the same today as it was then. Accordingly, the drawing tool is also an important tool in professional life.

What exactly is under one triangle ruler to understand?

The triangle ruler is used for drawings and angle calculations in mathematical geometry. It is actually a ruler, which is designed in the shape of an isosceles, right triangle, in combination with a protractor, For measuring and drawing angles is located on the triangle ruler a semicircle gauge with two opposing scales ranging from 0 degrees to 180 degrees. The outer edges of the Geodreieck form a triangle for the angle measurement. The triangle ruler itself is a triangle with angles of 45 and 90 degrees. Of course, there are different versions of the Geodreiecke – from the simple tool for the drawing and mathematics lessons to the TZ triangle for technical signs.

Different forms of the geodesic triangle

Some Geodreiecke have raised points on the bottom (Tuschenoppen). Others are equipped with a handle on the top. In addition, there are Geodreiecke with different length hypotenuses and thus in different sizes. The hypotenuse represents the ruler edge and carries a centimeter division whose zero point is in the middle. Starting from this zero point is a vertical center line, which divides the geodesic triangle into two halves and represents the height necessary for drawing right angles. In addition, parallel lines, which are aligned to the ruler edge, incorporated on the Geodreieck. Markings for different degrees of angle are mounted along the geodetic legs. This angle scale makes it possible to construct an angle with an accuracy of about half a degree. Drawings are made along the ruler edge. In addition to the half-right and right-hand angles, some geodesic triangles also have markings for angles of 7 degrees, 42 degrees, 138 degrees and 173 degrees, which allow an axonometric representation. Special Geodreiecke for navigation represent so-called course triangles.

Geodreieck – the application possibilities

Originally the Geodreieck comes in a modified form from the nautical. Today it is applied in math class geometry area. It can be used to draw straight lines, verticals, lines, angles and parallels. In the Geodreieck different protractors are combined. Especially in technical drawing Geodreiecke are often used in combination with a Abschiebedreieck or on a special tear rail. Especially for draftsmen, the drawing instrument has developed a permanent place in the workplace during the last decades. Technical draftsmen use it just as the captain of an overseas steamboat uses it to determine the course. Basically, the Geodreieck is everywhere at home, where it comes to the calculation of angles and straight lines must be drawn. The applications are varied. Whether as a simple ruler or as a combination tool – everyone can use a geodetic triangle.