I have created an arc using the Brush tool and now need to clip one end of it. If you refer to the attached image you will see that 1 is the arc created as a brush and 2 is what I wish to achieve by making the right hand end 'horizontal'. If I place a rectangle in front as shown in 3 and try to use a tool such as Pathfinder, I get a strange result as shown in 4. Because it is a brush there are no handles to allow me to reshape the end of the arc. Is there a way to achieve this. I need the final image to remain a vector as it will need to be resized. I am using Illustrator CS6.