Section 1a: Answer 3 questions (3 @ 5 pts. = 15 pts.)
1a.1 The three structural frames shown below are hinged at the four corners and are therefore unstable when subjected to a lateral load. Diagram three distinctly different strategies to make each structure stable. You can add members or alter the frames and connections as you determine effective. Note, a mirror image is not a distinctly different solution.
1a.2 Consider the parallel chord truss below which needs diagonals to be stable. Add diagonal members to the truss frame so that all the diagonals are in tension for the point load shown.