In this tutorial, you will create this part.
1.Click New. 
Click Part,
OK.
2.Click Front Plane 
and click on Sketch.
3.Click Rectangle, 
sketch rectangular. Click Smart Dimension, 
dimension rectangular 3in x 3in.
4.Click Feature>Extruded Boss/Base, 
set D1 to 1.0in and OK. 
5. Click on front face and select Normal to.
6.Click front face and Insert Sketch.
7.Click Circle, 
sketch circle at one edge.
8.Click Smart Dimension, 
dimension circle as below sketch.
9.Click Features>Extruded Cut,
set Direction 1, Through All and OK. 
10.Click Linear Pattern, 
click left edge,
on Direction 1 set spacing D1 to 1.0in and Instances # to 3.
11.Click bottom edge,
on Direction 2 set spacing D2 to 1.0in and Instances # to 3.
12.Click inside white box Features to Pattern.
Open up part tree, select Extrude 2
and OK.
13.You’re done!
