1. running in a slanting direction from one corner to another

1. a straight line connecting two opposite corners of a rectangle or other geometric figure

Examples

• She cut the fabric along a diagonal line.
• The diagonal stripes on his tie were blue and red.
• Draw a diagonal from the top left corner to the bottom right corner.
• The rectangle’s diagonal measures 10 inches.
• He walked diagonally across the park to save time.
• The diagonal of a square divides it into two equal triangles.