# True Length of a Segment

- Author:
- Johanna Zöchbauer, Andreas Lindner

- Topic:
- Geometry, Line Segment, Straight Lines

In the following coordinate system a segment s is given.
Besides, the segment s is drawn as s' in the plan view and as s'' in the front elevation.
The distance of point A from the xy-plane is called z

_{A}. This distance is equal to the z-coordinate of point A. The distance of point B from the xy-plane is called z_{B}.## Task 1

Click on "Top View" to see the segment from above.
Click on "Back", to return to the initial position.
Click on "Front View" to see the segement in the front elevation.
Click on "Back", to return to the initial position.

## Task 2

In which view is the segment displayed in true length?

## Task 3

Activate the box "Rotating Point A" and observe the changes in the coordinate system. What do you notice?

## Task 4

Activate the box "Rotating Point B" and observe the changes in the coordinate system. What do you notice?

## Task 5

Activate the box "Rotating the segment" and move the slider "Rotate s". What do you notice?

## True Length of Segment s

The true length of the segment s is now shown as s

_{0}in the plan view. The true length of a line is represented by a dotted line.