Step 2 – Geometry of deformation equation

(a) Draw the rotated position of the rigid bar and determine the relationship of the rigid bar deflections at $\mathrm{B}$ and $\mathrm{C}$ from similar triangles.

(b) Sketch the axial members after the rigid bar has rotated about $\mathrm{A}$. Determine the final length of each bar in terms of its initial length and the appropriate rigid bar deflection.

(c) Relate the member elongations to the rigid bar deflections.