 Constructions with ruler and compass
 Zef Damen
A page that answers the question, What are rulerandcompass constructions? With links to stepbystep drawings for constructions: bisecting a given angle; constructing: a line perpendicular to a given line that divides it into two equal parts; a line perpendicular to a given line passing through a given point on the line (or not on the line); the horizontal and vertical centerlines of a given circle; an equilateral triangle, given one side; an equilateral triangle inscribed in a given circle; a pentagon inscribed in a given circle; a hexagon, given one side, or inscribed in a given circle; a heptagon.
more>>
 Geometric Constructions  Dave Rusin; The Mathematical Atlas
An introduction to geometric constructions using a ruler and compass. History; applications and related fields and subfields; textbooks, reference works, and tutorials; software and tables; selected topics; other web sites with this focus.
more>>
 Geometric Construction with the Compass Alone  Interactive Mathematics Miscellany and Puzzles, Alexander Bogomolny
Information and exercises about geometric constructions: almost everything you can do with a ruler and a compass you can do with the compass alone.
more>>
 Geometry Construction Reference  Paul Kunkel
The basics of compass and straightedge construction, with notes about The Instruments and What is a construction? Construct the perpendicular bisector or the midpoint of a line segment; given a point on a line, construct a perpendicular line through the given point; given a point not on a line, construct a perpendicular line through the given point; construct the bisector of an angle; an angle congruent to a given angle; a line through a given point, parallel to a given line; an equilateral triangle or a 60degree angle; divide a line segment into n congruent line segments; construct a line through a given point tangent to a given circle; construct the center point of a given circle; a circle through three given points; circumscribe a circle about a given triangle; inscribe a circle in a given triangle.
more>>
 Impossible Constructions  Math Forum, Ask Dr. Math FAQ
Problems from antiquity: trisecting an angle, squaring the circle, duplicating (or doubling) the cube.
more>>
 The Many Ways to Construct a Triangle  Interactive Mathematics Miscellany and Puzzles, Alexander Bogomolny
In general, a triangle is defined by its three elements. SAS, ASA, and SSS provide three wellknown examples but there are many more. Bogomolny provides a table of constructions (linked to constructions) and invites reader contributions.
more>>
 
