Eight - four around the base, and one at each corner of the base converging to a point.
A square has four straight lines.
a square based pyrmaid has 24 lines of symitry
24
a pyramid has 4 straight edges
7
8 straight sides
A square has four straight lines.
8
24
24
24
24
Two pairs.
a square based pyrmaid has 24 lines of symitry
One. Vertical through the apex.
7
24