Using Fillet and Chamfer

FILLET is use to make radius on sharp edges of 2 connected lines.

Drawing toolbar

Draw menu: Fillet
Command entry keyboard: F 

Example:
command: 

1. Type F (then press enter)
2. Select first object or [Undo/Polyline/Radius/Trim/Multiple]: R (Tpye R for radius which is most use in fillet).
3. Specify fillet radius <5.000>: 5 (5 is the measurement of the radius)
4. Select first object or [Undo/Polyline/Radius/Trim/Multiple]: Click on first object as indicated on the figure 1.4. 
5. Select second object or shift-select to apply corner: Click on second object as indicated on the figure1.4.

Figure 1.4

CHAMFER is used to make angle on sharp corners of 2 connected lines.

Drawing toolbar

Draw menu: Chamfer

Command entry keyboard: CHA

Example:

command: 

1. Type CHA (then press enter)
2. Select first line or [Undo/Polyline/Distance/Angle/Trim/mEthod/Multiple]: A (A for angle)
3. Specify chamfer length on the first line <5.000>: 5 (5 is the measurement of chamfer)
4. Specify chamfer angle from the first line <45>: 45 (45 is the degree for the chamfer)
5. Select first line or [Undo/Polyline/Distance/Angle/Trim/mEthod/Multiple]: Click the first line as shown on the figure 1.5. 
6. Select second line or shift-select to apply corner: Click the second line as shown on the figure 1.5

Figure 1.5