I am trying to make a corner of a robot I am designing flush for aesthetic reasons as well as safety reasons but I'm not sure how to make the arch of the corner lay flush with the two lines that make up the edge.
Here is a photo of the side of the robot (top front of the starboard side). The green lines illustrate the perimeter, the gray arch shows the angle between the two green lines (which is 72.9 degrees), and the black arch is the arch that I would like to create. How can I find the correct radius for this black arch so it will connect the two sides without any angles?