Geometric Lines

Concept sheet | Science and Technology

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Definition

Geometric lines are sets of straight lines and curves forming geometric figures.

Straight lines and curves can be combined to form plane figures such as rectangles and circles. They can also be combined to form solids such as cylinders and cubes. The assembly of plane figures and geometric solids allows the technical drawing of various objects.

Geometric lines include various straight lines, circles and irregular curves.

Important!

Geometric lines created in a technical drawing must respect the conventions of basic lines.

Example

Here's a step-by-step example of the geometric lines of a flowerpot.

Step 1

An ellipse is drawn to represent the opening of the flowerpot, using an ellipse template.

Step 2

We draw two curves below the ellipse with the French curve to represent the flowerpot's borders.

Drawing of two curves under the ellipse.

Step 3

Using a ruler, we then draw two oblique lines connecting the ends of the ellipse with the ends of the curves to represent the sides of the flowerpot.

Drawing two oblique lines to represent the sides of the flowerpot.

Step 4

We erase the construction lines to obtain the final drawing.

A drawing of a flowerpot based on geometric lines.

Examples

Here are some more examples of geometric lines.

The representation of a round-bottom flask, an instrument used as a laboratory container, can be made by tracing a circle and adding a rectangle on top of it.

Technical drawing of a round-bottom flask based on geometric lines.

The technical drawing of a domino can be made by tracing a large rectangle containing circles of equivalent diameters.

Step 1

Step 2

Step 3

Step 4

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