Lesson focuses on how bridges are engineered to withstand weight, while being durable, and in some cases aesthetically pleasing. Students work in teams to design and build their own bridge Bridges must have a span of at least 14 inches and be able to hold the most weight. Students are encouraged to be frugal, and use the fewest amount of filament/supplies while still achieving their goals. Students then evaluate the effectiveness of their own bridge designs and those of other teams, and present their findings to the class.