Straight lines can point different ways. Stand up tall like a tree: that is a vertical line. Lie down flat like you are in bed: that is a horizontal line. Lean over like a slide: that is a diagonal line.
Key idea
Vertical stands up. Horizontal lies down. Diagonal leans.
Why it works
Horizontal comes from horizon, the flat line far away where the sky meets the land or the sea. Horizontal lines lie flat like the horizon.
Worked example: Let's look
The rungs of a ladder go across. Are they vertical or horizontal?
- The rungs lie flat, from one side to the other.
- Lines that lie flat are horizontal.
Answer: Horizontal.
Common mistake
Many people mix up vertical and horizontal. Use your body to remember: stand up for vertical, lie down for horizontal.