Ethan Clarke
A plastic triangle is a tool used in engineering and technical drawing to help create straight lines and accurate angles. It is a triangular piece of transparent plastic with the possibility of ruler and protractor markings. They are also known as set squares and come in two common forms, both right triangles: one with 90-45-45-degree angles and the other with 30-60-90-degree angles. They are economical and useful for students, but care must be taken to avoid warping or damaging the tips.
| Characteristics | Values |
|---|---|
| Material | Transparent plastic |
| Other materials used | Polished wood |
| Uses | Engineering and technical drawing |
| Function | Provides a straightedge at a right angle or other particular planar angle to a baseline |
| Common features | Markings of a ruler and a half-circle protractor |
| Outer edge | Bevelled |
| Common forms | Right triangles with angles of 90-45-45 degrees and 30-60-90 degrees |
| Combinations | Two forms can be combined to yield 15° and 75° angles |
| Sold with | Protractors and compasses |
| Variants | Larger sizes, fixed or detachable handles, with or without bevelled edges, with or without ink nodules or embossed labels |
| Markings | Extra markings at angles of 7° and 42° (138° and 173°) |
| Damage prevention | Lay flat or hang when not in use to prevent warping or chipping |
Explore related products
What You'll Learn
Uses: Engineering and technical drawing
A plastic triangle, also known as a set square, is a tool used in engineering and technical drawing. It is a triangular piece of transparent plastic with the centre removed to provide a straight edge at a right angle or other specific planar angle to a baseline.
The simplest form of a set square is a right triangle with either 90-45-45 degree angles or 30-60-90 degree angles. The outer edges are typically bevelled. These set squares often have markings similar to a ruler and a half-circle protractor. Combining the two usual forms by placing their hypotenuses together yields 15° and 75° angles. They are often sold in packs with protractors and compasses.
An adjustable set square is less common. It is made by cutting the body of the triangle in half and rejoining it with a hinge marked with angles. Some variants have extra markings at angles of 7° and 42° (138° and 173°) in addition to the normal 45° and 90° markings to ease dimetric axonometry. Other variants feature angle scales in gons instead of degrees.
When not in use, it is important to lay plastic triangles flat or hang them up to prevent warping or chipping. If a triangle is dropped and the tip is damaged, a sharp knife can be used to cut off the affected part. If the triangle is warped, one can try to bend it back by hand or leave it lying on a flat surface with weights on it. If the triangle becomes permanently warped, it will need to be replaced. To test the straightness of a triangle, place it against a T-square and draw a vertical line. Then, reverse the triangle and draw another line along the same edge. If the triangle is straight, the two lines will coincide.
Overlapping Corrugated Plastic Roofing: The Ultimate Guide
You may want to see also
Explore related products
History: Originally developed in 1964
The plastic triangle, also known as a set square, was originally developed in 1964 by the German manufacturer Dennert & Pape Aristo-Werke (now Geotec Schul- und Bürowaren GmbH). The plastic triangle is used in engineering and technical drawing to provide a straightedge at a right angle or a specific planar angle to a baseline. The simplest form of a set square is a triangular piece of transparent plastic with the centre removed, allowing the user to see their work underneath.
The use of triangles in drawing has a long history, with draftsmen combining triangles with T-squares to draw vertical and diagonal lines as early as the 19th century. These early triangles were made of materials such as wood, steel, and hard rubber. For example, in 1880, K&E sold a set of six hard rubber triangles with various angle sizes for depicting roof pitches in architectural drawings. By 1906, this set was made of transparent xylonite (plastic), and by 1909, K&E offered xylonite triangles specifically for use in engineering drawing.
The plastic triangle developed by Dennert & Pape Aristo-Werke in 1964 built upon these earlier uses of triangles in drawing. Their original design featured a hypotenuse length of 15.8 cm and included a 2x7 cm symmetry scale in millimetre and degree raster. Variants of the design were also offered in larger sizes, with fixed or detachable handles, bevelled or unbevelled edges, and with or without ink nodules or embossed labels.
Today, plastic triangles are commonly used in drawing and are available in various sizes and styles. They are typically referred to by the size of their acute angles, with the 45-degree and 30/60-degree triangles being the most common types. To maintain the accuracy of drawings, it is important to prevent warping or chipping of plastic triangles by storing them flat or hanging them when not in use.
Testing Plastic Brittleness: Methods and Best Practices
You may want to see also
Explore related products
Design: Typically a right triangle with bevelled edges
A plastic triangle is a tool used in engineering and technical drawing to create straight edges at right angles or other specific planar angles. It is also known as a set square. The simplest form of a plastic triangle is a triangular piece of transparent plastic with the centre removed.
The design of a plastic triangle is typically a right triangle with bevelled edges. The outer edges are bevelled to provide a straight edge at a right angle or a specific planar angle to the baseline. The bevelled edges also allow for accurate drawing and drafting. The two most common forms of plastic triangles are right triangles with angles of 90-45-45 degrees and 30-60-90 degrees.
Plastic triangles may also have markings similar to a ruler and a half-circle protractor. Some variants have additional markings at angles of 7 and 42 degrees (and their corresponding reflex angles) to aid in dimetric axonometry. The original design of the plastic triangle, developed in 1964, featured a hypotenuse length of 15.8 cm and a 2x7 cm symmetry scale in millimetres and degrees.
It is important to handle plastic triangles with care as they can be susceptible to warping or chipping. If a plastic triangle is dropped, the tip may become damaged, and the triangle may no longer lie flat on the drawing surface. To prevent warping, it is recommended to store plastic triangles flat or hung up when not in use.
The Plastic Lego's ABS Mystery Explained
You may want to see also
Explore related products
Function: Provides a straightedge at a right angle
A plastic triangle, also known as a set square, is a tool used in engineering and technical drawing to provide a straightedge at a right angle. It is a triangular piece of transparent plastic with the centre removed, allowing the user to draw straight lines at a precise right angle or other specific planar angles. The outer edges are typically bevelled.
The simplest form of a plastic triangle has a right angle (90 degrees) and two other angles that can be 45 and 45 degrees or 30 and 60 degrees. These triangles are often marked with a ruler and a half-circle protractor, making them versatile tools for drawing and measuring angles. They are commonly sold in packs with protractors and compasses, catering to students and professionals in fields such as engineering and architecture.
The straightedge function of a plastic triangle is essential for creating accurate drawings and technical plans. By providing a straight edge at a right angle, it enables users to draw vertical and horizontal lines with precision. This is particularly useful when creating multiple lines that need to be parallel or perpendicular to each other, ensuring uniformity and accuracy in the drawing.
To ensure the accuracy of the triangle, it is important to prevent warping. Plastic triangles should be stored flat or hung up when not in use. If a triangle becomes warped, it may no longer provide a true straight edge or right angle. In such cases, it can be attempted to be straightened by hand or by placing weights on it to counter the warping. If the triangle is permanently warped, it should be replaced.
The plastic triangle's functionality lies in its ability to maintain a true right angle and straightedge, making it a valuable tool for anyone who needs to create precise, accurate drawings, especially in technical fields.
The Unwanted Bits: Excess Plastic in Model Kits
You may want to see also
Explore related products
Maintenance: Prevent warping by laying or hanging flat
Plastic triangles, also known as set squares, are tools used in engineering and technical drawing to provide a straight edge at a right angle or a specific planar angle to a baseline. They are triangular pieces of transparent plastic with bevelled edges and markings of a ruler and a half-circle protractor.
To ensure the longevity of your plastic triangle, it is important to prevent warping. Warping can cause the triangle to not lie flat on the drawing surface, and the edge may deviate from its straightness. To prevent this, always lay the triangle flat or hang it up when not in use. Hanging is particularly recommended, as there may not be enough drawing space to lay the triangle flat.
If you drop your plastic triangle, you may damage its tip. If the tip is bent, use a sharp knife to cut off the damaged part. If the triangle is warped, you may be able to bend it back by hand. If bending does not straighten it, place the triangle on a flat surface with weights on it, or hold the triangle to the opposite curvature with weights.
If your triangle becomes permanently warped, with curved drawing edges or inaccurate angles, it is best to discard it and purchase a new one. To test the straightness of your triangle, place it against a T-square and draw a vertical line. Then, reverse the triangle and draw another line along the same edge. If the triangle is straight, the two lines will overlap. If they do not, the error is half the resulting space between the two lines.
The Easy Guide to Installing Plastic Backsplash Tiles
You may want to see also
Frequently asked questions
A plastic triangle is used in engineering and technical drawing to provide a straightedge at a right angle or other particular planar angle to a baseline.
A plastic triangle is also known as a set square.
The usual angles of a plastic triangle are either 90-45-45 degrees or 30-60-90 degrees.
Plastic triangles are more economical and less prone to damage than wooden triangles.
To test the straightness of a triangle, place it against a T-square and draw a vertical line. Then reverse the triangle and draw another line along the same edge. If the triangle is straight, the two lines will coincide.
