The Elements of Plane Geometry

ABCD altitude angle BAC angular points base BC bisector bisects the angle called centre chord circle ABC circumcircle congruent construction describe a circle described diagonal diameter difference distance divided draw drawn drawn parallel drawn perpendicular ends equal equilateral triangle equivalent EXERCISES exterior angle externally falls figure find the length follows formed four given point given straight line greater half Hence inscribed inside isosceles triangle join less Let ABC lies line drawn median meet meets BC mid-point MISC opposite sides orthocentre pair parallel parallel to BC parallelogram pass perpendicular polygon produced PROP prove quadrilateral radius ratio rect rectangle contained respectively right angles segments side BC similar Similarly square taken touch triangle ABC twice vertical