Which tool used to draw thick and thin lines in MS Paint?

 In MS Paint, lines are fundamental element of a drawing. You can draw different types of line for your drawing. The most popular types are thin and thick lines within you drawings.

Tool to use for thick and thin lines

Open you MS Paint software as shown on the figure below. Under Home > Shapes > Select the Line shape.

Select Line Shape

Choose Size and Color

Next to the line shape is the size and color for the line shape. 

Choose line Size and Color

Start drawing thin or thick lines

In the drawing area, now you can start making  straight thin or thick line like the following image.

A House- Only using lines