Bridges

1. Arch bridge- The Arch bridge includes shapes, such as half circles on the bottom, and triangles and rectangles on top. If you push on the top of the bridge, the structure exerts out. If you pull the bridge out, the rest of the bridge expands out with the rest of the bridge.

2. Truss bridge- The Truss bridge is made of many triangles, squares, and rectangles. When you push or pull on the bridge, the bridge does well with compression, and has close to no movement. This bridge is very sturdy and is wider at the bottom and thinner at the top.

3. Suspension bridge- The suspension (cable) bridge is made of rectangles. If you push on the middle of the bridge, the poles go inward as well as the rest of the bridge. If you pull on the string of the bridge, outward, the rest of the bridge moves outward as well. The bridge does not have a lot of compression, which allows the bridge to swing back and forth.