1.Select the Curve Modeling tab from the top Ribbon Bar.

2.Keep the Curve Modeling Ribbon Bar displayed.

3.Select the Circle Center, Center, On Pt icon.
 

The command input bar would now prompt you to specify the center for the circle.
 
Command Prompt:
Center, On Pt:: Pick center point or enter coordinates x,y and z

4.For the center point, pick last created point or type 7,0
 
Command Prompt:
Center, On Pt:: Enter point on circle::[D=0.500000]

5.Specify 1.50 for Diameter in the command bar and press Enter.
 
The created circle is as shown below.

6.Repeat the Circle command to create 2 more circles at the center points (2.5,0 and 5,0) enter a Diameter of 1.00 for each circle.

7.From the Status Bar, toggle Grid Snap off and then toggle Quad Point Snap on.
 

8.Select the Create Single Line icon.
 

9.Create a line between the top quadrants points of the smaller circles.

10.Repeat the line for lower quadrant points.