In geometry, true length is any distance between points that is not foreshortened by the view type. Lines with true length are parallel to the projection plane. For example, in a top view of a pyramid, which is an orthographic projection, the base edges (which are parallel to the projection plane) have true length, whereas the remaining edges in this view are not true lengths. 

Task: Sketch a square pyramid in orthogonal and label true length lines.

Task: Go to the HSC Questions for this topic. Can you give the correct answer for each question?