Two points and the ordinate
SŠ7 minWhy the top and front views share a vertical ordinate – and how that compares two points.
Orbit the space
Theory
Every point has its own ordinate – the vertical line carrying both of its views. Two points therefore sit on two different ordinates, and their horizontal spacing on the drawing is exactly the difference of their x-coordinates.
You always read the height (z) from the front view: the higher above the ground line, the higher in space. You read the depth (y) from the top view: the further below the ground line, the further in front of π₂. Each coordinate has exactly one view that can report it.
One special case is worth remembering: if two points share an ordinate they share x. If one of their views also coincides they are so-called covering points – they merge in that view and only the other view tells them apart.
Step-by-step construction
Practice
Build the construction yourself
What is the next step?
1 / 4Choose the step that comes next. The drawing only advances on a correct choice.
Check your understanding
Which view do you read a point’s height above π₁ from?
Two points lie on the same ordinate. What is certainly true of them?
Point B has a greater depth than point A. How does that show on the drawing?
Downloadable material
A PDF for this lesson is in preparation.
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