Page 5.4

Now it's time to introduce some names for what we have encountered so far. Lets start with the wall. Looking at the wall we know it is vertical, and the name we use for a flat surface in Technical Graphics is a 'Plane'. Therefore the wall is also called a 'Vertical Plane', or 'V.P.' for short. We can apply the same logic to naming the floor, what is the floor if the wall is vertical ? yes, it's horizontal, and it is also a 'Plane', so we call the floor a 'Horizontal Plane', or 'H.P.' for short. For now, just remember the line of intersection, or the line where the H.P. and the V.P. meet is called the 'XY'. (we will be dealing with this at a later stage.)

Now lets see how well you understand that. Take a look at the drawing below, and

1. Click on the Horizontal Plane,
2. Click on the Vertical Plane,
3. Click on the XY line.

(The area you have clicked on will be named in the bottom frame, see if you choose the correct one yourself.)