d$.(2$ pts$)$ Sketch and label the angle ${}_{\frac{C}{D}}$ on the elastic curve shown. Be sure to indicate the proper direction for this angle.

e$.(2$ pts$)$ Sketch and label ${}_{\frac{B}{A}}$ on the elastic curve shown. Be sure to indicate the proper direction for this quantity.

f$.(4$ pts$)$ When using the Virtual Work method to solve for deflections, describe, using words, where the unit virtual load is placed.