The Science of Living Things series demonstrates that Bobbie Kalman and her staff have turned out yet another informative and finely produced series of books. . . . this whole series would make a welcome addition to the elementary school library -- Kay Lehr, Fort Rouge School, Manitoba, Jan. 1999.
perpendicularity - the quality of being at right angles to a given line or plane (especially the plane of the horizon) oblongness, rectangularity - the property of being shaped like a rectangle.
Historically, ellipticity is the unit of circular dichroism and is defined as the tangent of the ratio of the minor to major elliptical axis. Axial ratios of 1:100 will then result in an ellipticity of 0.57 degrees. Modern CD instruments are capable of millidegree precision.