Defect circumferential location, circumferential length and depth are studied with an ultrasonic guided wave focusing inspection technique. Differently shaped defects, such as a planar saw cut, a volumetric through-wall hole, and a volumetric spherical shape corrosion are studied. By focusing on 44 circumferential positions around the pipe at a specific distance, the maximum amplitude of the defect echo is recorded with respect to each circumferential focal position. Circumferential lengths of the planar saw cut and volumetric through-wall hole are then measured by comparing the experimental results with theoretical calculations. It is shown that this measurement technique works well with the planar saw cut and volumetric through-wall hole defects. In addition, it is shown that reflections from defects with the same cross sectional area (CSA), but different shapes, might be very different.