In this unit, the students will investigate buildings around them. They will identify the shapes present within buildings and they will create a fair test to explore the strength of these shapes. They will understand that triangles are used within structures because of the strength of this shape. The students will then investigate different types of bridges. They will sort pictures of bridges and attempt to identify the main types of bridges. The students will then research the features of a particular type of bridge, for example, a suspension bridge. They will recognise how the bridge supports its weight and the weight of its load. They will also become aware of the situations where these bridges are most suited. Finally they will use the information that they have gathered about bridges, to design and make a model of a bridge. There are also suggestions on how an interactive website can be used to further enhance this unit.