# Bridges: Human links and innovations

## CONTENTS OF CURRICULUM UNIT 01.05.09

- Narrative
- Contents of Curriculum Unit
- Opening Statement
- History of Bridges
- Bridges
- School Description
- At Risk Students
- Geometry
- Research On The Internet
- Materials Used For A Bridge
- Mathematical Scaling
- Field Trips
- Conclusion
- Lesson Plan I
- Lesson Plan II
- Lesson Plan III
- Bibliography
- Student Reading List
- Teacher Reading List
- Links

### Unit Guide

## Geometry of Bridges

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## Geometry

Incorporating geometry in with bridges serves two purposes: the study of shapes and symmetry and the function of design. The shapes of geometry: squares, triangles, rectangles, and other geometric shapes can work in the designing of a bridge. The function or use of these geometric designs will show the students that geometry is important. Students working with different three-dimensional shapes will explore how and where the students can use these shapes in their bridges. The shapes can be tested to see which designs are the strongest how much weight can they hold or what pressure can be applied to see the breaking point. This will help the students in their design. Also the students need to explore how they can build a strong bridge with the use of a minimum of material. Sometimes the availability of materials can dictate the design of the bridge. The strength of the bridge is not necessarily determined by the bulk of material.
In geometry the students will need to understand certain geometric terms:

Some terms in physics will also need to be discussed:

- 1. Lines-A line extends forever in two directions
- Types of lines:
- ____ a. A ray extends forever in one direction
- ____ b. A line segment is a line between two points
- ____ c. Parallel lines are lines that do not intersect
- ____ d. Perpendicular lines are two lines that intersect at a right angle
- 2. Angles-An angle consists of two rays that meet at the same point, which is called the vertex.
- Types of angles:
- ____ a. Acute angle-measures between 0° and 90°
- ____ b. Right angle-measures 90°
- ____ c. Obtuse angle measures between 90°and 180°
- ____ d. Straight angle measures 180°
- 3. Symmetry:
- Symmetry is when a figure can be divided by a line and both resulting halves are equal-mirror images of the other.
- 4. Triangles-A polygon with three sides
- Types of triangles:
- ____ a. Scalene triangle-all sides have different lengths
- ____ b. Isosceles triangle-at least two sides have the same length
- ____ c. Equilateral triangle-all three sides have the same length
- Triangles identified by their angles
- ____ a. Acute triangle has three angles that are acute
- ____ b. Obtuse triangle has one angle that is obtuse
- ____ c. Right triangle has one angle that is a right angle
- 5. Quadrilaterals-A polygon with four sides
- Types of quadrilaterals
- ____ a. Parallelogram is a quadrilateral with opposite sides parallel
- ____ b. Rectangle is a quadrilateral with four right angles
- ____ c. Square is a rectangle with sides of equal lengths
- ____ d. Rhombus is a parallelogram with sides of equal length
- ____ e. Trapezoid is a quadrilateral with only one pair of parallel sides
- ____ ____ 1. A trapezoid is isosceles if its non parallel sides have the same length
- 6. Regular polygons have sides that are the same length and angles that have the same measurement.
- 7. Polyhedron-is a solid that is bounded by polygons, which are called faces. The segments where the faces meet are edges, and the points where the edges meet are vertices
- Types of polyhedrons and solids:
- ____ a. Prisms
- ____ b. Pyramids
- ____ c. Sphere
- ____ d. Cylinder
- ____ e. Cone

Compression, tension, live load, and dead load.