4 or 8 Four (the edges of the base square)
Perhaps four more, depending on the height of the pyramid, the opposing edges could be perpendicular to each other at the apex.
Including its diagonals there are 6 perpendicular lines
4
24
24
24
24
Including its diagonals there are 6 perpendicular lines
Do pyramids have perpendicular faces ?
A trapezium has no right angles therefore there are no perpendicular lines. If it had perpendicular lines, it would be a square or rectangle.
4
7
24
24
24
4
Two pairs.
4, one set at each corner.