8
10
I need 100 straws.
18 straws.
15 straws are needed
12
8
8
10
6 straws are needed
16 straws.
8
8 straws 4 for the square base 4 for 1 each of the sides, to meet at the top.
A square based pyramid has 8 edges: One for each side of the square, and one from each corner of the square going up to the point.
depends on the dimensions of the 4 sides
6
Eight.