Line Types
Horizontal Lines
To draw Horizontal lines, make sure you place the stock of the tsquare up against the edge of your drawing board. Make sure you place your left hand on the stock of the tsquare this insures that the tsquare remains in against the board. You can then draw the line from left to right with your right hand.

Vertical Lines
To draw vertical lines on your sheet, place the set square up against the blade of the tsquare and ensure the stock of the tsquare is against the drawing board. Your left hand should be placed on the blade of the tsquare and the set square in order to keep both in position and steady. Draw the line from top to bottom with your right hand.

Parallel Lines
Lines going in the same direction and the same angle are called parallel lines.
Shown on the left is a video on how to construct parallel lines. 
Perpendicular Lines
Perpendicular lines are lines that intersect at 90°
Shown on the left is a video on how to construct a perpendicular line to an already existing a line. 
Construction Lines
Heavy Lines
Heavy Lines are lines used to show the outline of the object you are drawing. There are represented by a continuous heavy line. These lines are drawn by leaning on your pencil a lot harder than when drawing construction lines but not hard enough to crack the pencil point. There should be a clear difference in line thickness between heavy lines and construction lines. Shown on the left is a heavy line.
