Creo Simulate > References > Sketcher > Creating Sketcher Geometry > To Create a Circular Fillet
  
To Create a Circular Fillet
1. Click Sketch and then click the arrow next to Fillet.
2. Click Circular.
3. Select the first line to be connected. Make sure to select the point at which you want to place the fillet.
4. Select the second line to be connected at the approximate point at which you want to place the fillet. The fillet is created between the points you selected and the lines are trimmed. Construction lines extend to the intersection point.