Robbin's New Plane Geometry

ABCD acute angle altitude angle formed apothem base bisector bisects central angles chord circumference circumscribed circle congruent construct a square construct a triangle COROLLARY diagonals diameter divided equal angles equal circles equal in area equal sides equally distant equilateral triangle exterior angle figure Find the area given circle given line given point given triangle Hence homologous sides hypotenuse inches inscribed angle inscribed regular isosceles trapezoid isosceles triangle line is drawn line joining mean proportional median meeting number of sides opposite sides pair parallel parallelogram perimeter perpendicular produced Proof Prove Q.E.D. PROPOSITION quadrilateral ratio rectangle regular hexagon regular polygon rhombus right angle right triangle secant segments similar polygons square equal straight line tangent THEOREM transversal trapezoid triangle ABC triangle equal vertex angle vertices