(Structural Eng.) Three of the most commonly used beams in structural engineering are the I-beam, rectangular beam, and cylindrical beam, shown in Figures 4.6 through 4.8. In determining the stress a given weight places on a symmetrical beam, an important design parameter is the beam’s rectangular moment of inertia, I, which is typically given in units of in4 . The computation of I depends on the beam’s geometry, and for the three beam types shown, the values of I are calculated as follows:

For an I-beam: where all measurements are in inches

For a rectangular beam:

For a cylindrical beam:

Figures 4.6 through 4.8 show the variables b, h, B, H, and r. Using this information, design, write, compile, and execute a C++ program that prompts the user for the type of beam and the necessary data (based on the input), and then computes and displays the beam’s rectangular moment of inertia.