t-square

T-Square
The grey T-Square looks like the letter T. Notice that the top of the t-square is horizontal and the long part is vertical. In order to use the t-square correctly you need to tape your paper to a drawing board, making sure that the edges of the paper are paralel to the edges of the drawing board. Then, by sliding the t-square along the side of the drawing board you can draw parallel or perpendicular lines.