Select the Shape Editor Tool and create a line as shown above. Click to add new points and line sections. The line has to pass between the tangency of the three circles and has to exit just to the left of the bottom most circle. Take your time and get it right. Select the line and the large circle. From the Arrange menu, select Combine Shapes > Slice Shapes (Ctrl 4). This slices the circle into two parts. Delete the left half. Select all of the circles (except the small circle shown in red) and the large half circle shape, and Arrange > Combine Shapes > Add Shapes  (Ctrl 1). Select the red circle and the combined shape and Arrange > Combine Shapes > Subtract Shapes (Ctrl 2). The red shape has to be in front (Arrange > Bring to Front or Ctrl f) to subtract shapes. A lot of work to create one fan blade! Reduce the blade 50%. Click twice for rotate/skew mode. Drag the Center of Rotation bulls eye down beyond the bottom center of the blade. RIGHT click rotate and duplicate to add the other three blades.