APPLIED MATHEMATICS E-NOTES, vol.6, pp.26-32, 2006 (ESCI)
In this paper, we present the Steiner formula for one-parameter open planar homothetic motions. Using this area formula, the generalization of the Holditch Theorem given by W. Blaschke and H. R. Muller [4, p.142] is expressed during one-parameter open planar homothetic motions. Furthermore, we obtain another formula for the swept surface area.