Thetford Bridge on the eastern edge of Vermont dates from the mid-1800s. The sides of the span are supported by a Haupt truss, making it the only wooden bridge of its kind in Vermont and one of only three such bridges in the United States. For Problems 1-5, use the graph. 1. The design of a Haupt truss is based on parallelograms. The graph shows two parallelograms in the truss. Prove that figure A is a parallelogram by showing that its opposite sides are congruent. 2. Each acute angle of the parallelogram measures 63. What is the measure of each obtuse angle? (Hint: Opposite angles of a parallelogram are congruent.) 3. Parallelogram A is transformed to make part of the pattern of the truss. Describe the transformation that moves parallelogram A to parallelogram B. 4. To complete a section of the truss, the set of parallelograms shown in the figure is reflected across the y-axis. Draw the completed section. 5. Describe any symmetry in the completed section of the truss. 4 2- A B X -2 0 2 4 6 8