Answer Key: Self-Test C-3.4

Identify each type of line in Figure 1 below by stating:

1. its name (visible line, hidden line, centre line, etc.)
2. its main use (shows object outline, shows centre of hole, shows location of sections, etc.)

1. Line 1
   1. outline
   2. outline of a part
2. Line 2
   1. centre line
   2. centre of an object
3. Line 3
   1. phantom
   2. shows location of removed parts not detailed
4. Line 4
   1. dimension line
   2. shows dimension of a part
5. Line 5
   1. extension lines
   2. shows where a dimension is taken from
6. Line 6
   1. leader line
   2. points out a dimension or part
7. Line 7
   1. hidden
   2. shows hidden surfaces