A treatise on special or elementary geometry (1877)
Olney, Edward, 1827-1887, Olney, Edward, 1827-1887. Elements of trigonometry, plane and spherical · New York : Sheldon · leaf 115
mmon tangent to two circles tangent to each \ q^^ rj,^ ^^i Exercises -i -^^^^ ^^ ^^^^ circumference through three points. I Prob. To circumscribe a triangle with a circumference. 94. ELEMENTABY PLANE GEOMETRY. SECTION VL OF THE MEASUREMENT OF ANGLES. 200» Angles are said to be measured by arcs,… … let arc AB = arc DC; then will theangles O and 0, called angles atthe centre, be equal. For, placingN upon M so that C shall fallon 0, and CD on OA, sincethe circles are equal, D will fallon A; and since, by hypothesis,arc DC = arc AB, C will fall onB. Hence, OC will coincidewith OB, and angle O =…
Geometry · Trigonometry
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