HG91009

The steps for the design of this exercise in AutoCAD are as follows:

Command: LIMITS
Reset Model space limits:
Specify lower left corner or [ON/OFF] <0.00,0.00>: 0,0
Specify upper right corner <420.00,297.00>: 70,50

Command: LINE
Specify first point: 0,0
Specify next point or [Undo]:  <Ortho on> 62
Specify next point or [Undo]: 40
Specify next point or [Close/Undo]: 12
Specify next point or [Close/Undo]: 28
Specify next point or [Close/Undo]: 35
Specify next point or [Close/Undo]: 18
Specify next point or [Close/Undo]: 15
Specify next point or [Close/Undo]: CLOSE

Command: REGION
Select objects: Specify opposite corner: 8 found
1 loop extracted.
1 Region created.

Command: EXTRUDE
Current wire frame density:  ISOLINES=4, Closed profiles creation mode = Solid
Select objects to extrude or [MOde]: 1 found
Specify height of extrusion or [Direction/Path/Taper angle/Expression]: 40

Command: RECTANGLE
Specify first corner point or [Chamfer/Elevation/Fillet/Thickness/Width]: 13,0
Specify other corner point or [Area/Dimensions/Rotation]: @14,18

Command: EXTRUDE
Current wire frame density:  ISOLINES=4, Closed profiles creation mode = Solid
Select objects to extrude or [MOde]: 1 found
Specify height of extrusion or [Direction/Path/Taper angle/Expression] <40.00>: 12

Command: SUBTRACT
Select solids, surfaces, and regions to subtract from ..
Select objects: 1 found
Select solids, surfaces, and regions to subtract ..
Select objects: 1 found