The figure shows the deflection suffered by the supporting rods. The deflection at point B which is 380 millimeters to the right of point A is v subscript B and the deflection at point C which is 760 millimeters from point A is v subscript c.

Substitute

vB=δ1vC=δ2

into the equation relating the rigid bar deflections

vB380 mm=vC760 mm

to obtain the geometry of deformation equation:

δ1380 mm=δ2760 mm