When two dimensional objects are drawn on a flat surface, they can be represented in one of two ways: first angle or third angle projection. In first angle projection, the object is drawn as seen from the front, with all views arranged around it. Third angle projection is the opposite – the object is drawn as seen from the back, with all views arranged around it.
So, what’s the difference between these two methods? First, let’s take a look at an example:
Here we have a simple cube. If we were to draw this in first angle projection, it would look like this:
As you can see, the front view (which is technically called the top view) is placed directly above the object. The other views are then placed around it, with the right side view to the right of the object, and so on.
In third angle projection, the cube would look like this:
As you can see, the back view (which is technically called the bottom view) is placed directly below the object. The other views are then placed around it, with the right side view to the left of the object, and so on.
So what’s the difference between these two methods? Well, first angle projection is used mainly in Europe, while third angle projection is used mainly in America. There are also some subtle differences in how the objects are drawn – in first angle projection, hidden lines are usually drawn in dashed lines, while in third angle projection, they are usually drawn in dotted lines. However, these differences are not absolute – both first and third angle projection can be used with either dashed or dotted hidden lines.
In the end, which method you choose depends on personal preference – there is no right or wrong way to draw an object. Both methods produce accurate and useful drawings that convey all of the information needed for proper interpretation. So if you’re unsure about how to proceed when drawing a two dimensional object, don’t worry – there’s no ‘right’ answer! Just pick whichever method seems most comfortable to you and go from there.
Do you have any questions about first angle or third angle projection? Let us know in the comments!
