Save guides, add subjects and pick up where you left off with your BBC account. Straight lines can be drawn in any direction. Horizontal lines go left and right. Vertical lines go up and down.

It shows a cafe wall having horizontal and vertical lines. But do these horizontal lines bend at a specific angle, or are they straight? This cafe wall optical illusion has left people scratching ...

will either be a horizontal or vertical line ... the equation of the line will be of the form \(y = …\). The equation of a straight line on a graph is made up of a \(y\) term, an \(x\) term ...