Figure 1

What completed drawing will be

Figure 2

Draw these three shapes

Figure 3

First shape extruded

Figure 4

Using existing extrusion as template

Figure 5

Second shape extruded

Figure 6

Extruding small box

Figure 7

Moving parts into place

Figure 8

Parts assembled

Figure 9

Hidden edge applied

Figure 10

Lines added

Figure 11

Finished Crossblock