How can I draw a straight line?
GIMP has no specific tool for drawing a straight line, but you can draw one with any painting tool. After choosing the drawing tool and setting the parameters, click the first point of the line and then press the key and place the endpoint. You can even draw a polygon in this way, by pressing and clicking at each corner of the shape.
How can I draw a circle?
We explain this in detail in Drawing Ellipses and Rectangles. The simplest solution is to stroke a circular selection, but you can create a ring-shaped ...