To draw a curved line
In the toolbox, click Curve .
Below the toolbox, click a line width.
Draw a straight line by dragging the pointer.
Click where you want one arc of the curve to be, and then drag the pointer to adjust the curve. Repeat this step for a second arc. You can only create two curves for each line.
When you drag the pointer, the foreground color is used. To use the background color, click and hold down the right mouse button and drag the pointer.