Illustration of supplementary angles. Two angles whose sum is a straight angle. This can be used tow show the Theorem: If two adjacent angles have their exterior sides in a straight line, these angles are supplementary.
Keywordsgeometry, angle, angles, sum, supplementary, 180 degrees, straight line, supplement, supplements
G.A. Wentworth Plane And Solid Geometry (Boston: Ginn & Company, 1899) 16