High school Design and Technology students often need to know how to draw an ellipse using an accurate method. This article explains how to construct an ellipse using the concentric circle method, as well by use of a trammel.
What is an ellipse?
An ellipse is often described as a “stretched circle.” It is a specific type of oval with precise mathematical properties. It has a major axis (longest diameter) and a minor axis (shortest diameter) that intersect at the centre.
When you view a circle at an angle, it appears as an ellipse. For example, when drawing the top of a cup, artists will often draw an ellipse. The more extreme the viewing angle, the more elongated the ellipse appears.
Ellipses are found throughout nature and technology – from planetary orbits to architectural elements like arches and domes.
How to draw an ellipse using the concentric circles method
- Draw the major axis and minor axis using horizontal and vertical lines;
- Draw two circles with diameters equal to the major and minor axes;
- Divide up the circles into 12 equal segments using 30/60 set squares;
- Where segment lines cross the smaller circle, draw a horizontal line;
- Where segment lines cross larger circle, draw a vertical line;
- Each intersection point between vertical and horizontal lines is a point on the curve of the ellipse.
- Join the intersection points with a freehand curve (take care to ensure the end of the ellipse is a smooth curve, rather than pointy);
- Note: horizontal / vertical lines are switched for an ellipse that is orientated vertically.
How to construct an ellipse using a trammel
[coming soon]
Amiria has a Bachelor of Architectural Studies, Bachelor of Architecture (First Class Honours) and a Graduate Diploma of Teaching. She is a CIE Accredited Art & Design and Design & Technology Coursework Assessor. Amiria now teaches Art, Design & Technology at ACG Parnell College.