A scrap-book of elementary mathematics; notes, recreations, essays (1908)
White, William Frank, 1871- · Chicago, The Open Court Pub. Co · leaf 140
INSTRUMENTS POSTULATED. 131 Proof. ZPBC = its alternate ZBPM. Mark N the mid-point of PQ, and draw NM. Then N, the mid-point of the hypotenuse of the rt. A PQM, is equidistant from the vertexes of the triangle. .•.ZBPM = ZPMN Exterior ZBNM = ZBPM + ZPMN = 2ZBPM … Fig. 19. •.•NM = iPQ-BM .-. ZMBN = ZBXM ZPBC = ZBPM = iZBXM = iZABN = ^ZABC.
Mathematical recreations
Internet Archive · Cornell University Library · Public domain (published before 1931). Free to use for anything.
