The elements of geometry, in eight books; or, First step in applied logic

altitude angles formed base bisectrix called centre centre angle centre line chord circle circumference coincide common Const construct contained conversely COROLLARY II DEFINITIONS diagonals diameter difference direction divided draw drawn equally distant equivalent Eucl evident extremities formed four Geometry given given straight line greater hence homologous hypothenuse infinitely inscribed intercepts intersection joined latter less Let A B lines joining magnitude mean measure meet middle line middle perpendicular middle point opposite parallel parallelograms pass perimeter perpendicular placed point of tangence polygon portions PROBLEM produced proportional quadrangle quantities radii radius ratio reasoning rectangle regular polygon respectively right angles right-angled triangle Scholium secant sector segment sides similar square straight line subtending surface symmetric tangent thence THEOREM third triangle A B C unequal unit vertex vertices W. W. T. B. D. COROLLARY