The normal elementary geometry : embracing a brief treatise on mensuration and trigonometry : designed for academies, seminaries, high schools, normal schools, and advanced classes in common schools (1884)
Brooks, Edward, 1831-1912 · Philadelphia : Christopher Sower Co. · leaf 211
PLANE TRIGONOMETRY. 15 15. The Tangent ofan arc is a line which is perpendicularto the radius at one extremity of the arc, and limited by a linepassing through the centre of the circle and the other extremity;thus, AT is the tangent of AC. 16. The Cotangent of an arc is equal to the tangent of…
Geometry · Plane trigonometry
Internet Archive · Cornell University Library · Public Domain Mark 1.0. Free to use for anything.
