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 ?
In a trapezium, there are two perpendicular lines. These perpendicular lines are the diagonals of the trapezium. The diagonals of a trapezium are the line segments that connect non-adjacent vertices of the trapezium and intersect each other at a right angle.
4
24
24
24
4
Two pairs.
a square based pyrmaid has 24 lines of symitry
4, one set at each corner.