The ‘mental number line’ theory doesn’t appear to hold up vertically. In A Nutshell When people viewed vertical lines filled ...

Straight lines can be drawn in any direction. Horizontal lines go left and right. Vertical lines go up and down. Parallel lines are a fixed distance apart and will never meet, no matter how long they ...

Whether you are sketching graphs in mathematics, understanding directions in geography, or reading blueprints in design class, horizontal and vertical lines are concepts you cannot avoid. They form ...