How to Draw Orthographic Projection for Beginners: a step by step guide

Orthographic projection is a planar drawing method that shows shows ‘flat’ 2D views of the object from different angles. It is a technical drawing method that is usually drawn to scale and may include dimensions. This tutorial introduces students to this method and concludes with sample examination questions.

orthographic projection using third angle
Example: This shows an orthographic drawing of the isometric block drawn on the right. Note that it shows views of the object as if viewed from different directions. Each view is separated by ‘reference plane‘ lines (these are drawn as long dash, two short dashes).

Common orthographic views are:

  • Plan view (view from above)
  • Front view (usually the largest or most complicated view)
  • Side views (end views)
  • Sectional views (views showing what an item looks like when sliced or cut away)
third angle orthographic drawing
An example of third angle orthographic projection. Note that hidden details are shown as dashed lines; centre lines as long dash, short dash; and reference plane lines separating the views as long dash, two short dashes.

Orthographic drawings are commonly used for working drawings. Working drawings are precise, accurate drawings that a manufacturer can directly measure from to build or make the product or design.

First Angle or 3rd Angle Orthographic Projection

There are two main types of orthographic drawing: first angle and third angle. These differ in terms of where the views are placed on the page.

  • First angle: the top view is below the front view, and the right side view placed to the left of the front view (illogical layout);
  • Third angle: the top view is above the front view, and the right side view is placed on the right of the front view (logical layout).

The orthographic drawing symbol is included on a drawing to tell viewers which method has been used (the symbol is a tiny orthographic drawing of a truncated cone – a cone with its top chopped off).

NOTE: Because Cambridge Design & Technology is an international exam, either type may be referenced. Designers need to be familiar with both systems to work effectively in global contexts.

How to draw orthograph projection step-by-step

What follows is a short tutorial explaining how to complete a third angle orthographic drawing of the following simple 3D block.

Orthographic projection: how to draw the plan view
STEP 1: In this case, we begin by drawing the view from above (the plan view), ensuring measurements (if known) are accurate and to scale. Note: There are no rules about which view you should start with, but the plan view is often a simple place to start. Because we are using third-angle orthographic we will position the plan view at the top of the page (logical layout). When constructing the plan view, lines should be exactly horizontal or vertical. Dashed lines have been used to represent hidden detail. In Cambridge examination questions, hidden detail lines should only be added if specifically requested, as this takes extra time and can clutter a drawing.
Orthographic drawing reference planes
STEP 2: Now we will add in reference plane lines (sometimes just referred to as ‘reference lines’), using the long dash, two short dashes line symbol. These lines separate the views and make it clear where one view stops and another begins. The exact position of the reference line doesn’t matter, as long as they are placed somewhere in between the views.
45 degree line in orthographic projection
STEP 3: Where the reference lines meet, add in a light 45° line (also known as a ‘bounce line‘). As you will see shortly, this line helps with transfer measurements from one view to another.
orthographic drawing projection lines
STEP 4: Add light construction lines projecting widths downwards from the top view. This ensures the front view is exactly in line with the top view and saves you from re-measuring all the widths. This is one of the great benefits of orthographic projection. Once you have completed the first view, it is much faster to draw the other views. These lines must be very light, to avoid cluttering the drawing. They should not be erased as these show examiners how the drawing has been constructed (like showing your working in mathematics).
Orthographic drawing front view
STEP 5: Complete the front view, ensuring heights (if known) are added accurately and to scale. There are no rules about exactly where on the page the front view is positioned, however it should be exactly below the plan view, and below the reference line.
orthographic drawing side view
STEP 6: Now we are going to construct the side view. As before, we begin by projecting heights across from the front view.
Orthographic drawing constructing end view

STEP 7: Now we are going to use the 45° line to transfer the widths from the plan to the end view. We begin by projecting widths across from the plan until they hit the 45° line.
Step by step orthographic drawing
STEP 8: Where these lines hit the 45° line, we now bounce the widths downwards. This makes it much faster to complete the end view, as we don’t need to measure the heights or the widths.
orthographic projection using third angle
STEP 8: Now we can complete the side view, darkening outlines and adding in hidden detail as required. Note that the outlines should be much darker than the construction lines.

Sample exam questions (0445 IGCSE Paper 5)

orthographic project IGCSE Design & Technology exam

Note: See how to draw an ellipse here.

Examiner comment:
(i) This part of the question required candidates to draw the side view of the box. Many candidates achieved full marks for this but the accuracy of some responses was not strong.

(ii) This part of the question required candidates to complete the side view of the ready meal box. Candidates who projected the front view from the side view achieved the best results.

(iii) Candidates were required to construct the ellipse. Many candidates did not achieve full marks on this question. Some candidates used incorrect construction methods or joined the plotted points of the ellipse with straight lines rather than a smooth elliptical shape Where a trammel is used for constructing an ellipse, this must be attached or drawn adjacent to enable marks for construction to be awarded.

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