Davies, Charles, 1798-1876 · New York and Chicago, A. S. Barnes and company · leaf 160
Cor. The surface described by any portion of the perim-eter, as EDO, is equal to the distance between the two per-pendiculars let fall from its extremities, on the axis, multipliedby the circumference of the inscribed circle. For, the sur-face described by DE is equal to HIx circumference ONand the… … THEOREM XXIII. The surface of a sphere is equal to the product of its diameterby the circumference of a great circle. Let ABODE be a semicircle. In-scribe in it any regular semi-polygon,and from the centre O draw OF per-pendicular to one of the sides. Let the semicircle and the semi-polygon be…
Geometry · Plane trigonometry
Internet Archive · Library of Congress · Public Domain Mark 1.0. Free to use for anything.
