Compass Construction 3: Classifying Quadrilaterals and Triangles

This GeoGebra example demonstrates how to construct various quadrilaterals and triangles using compass and straightedge, and automatically classify them based on geometric properties. Core math concepts include parallelism, perpendicularity, diagonal properties (equal, bisecting, perpendicular), isosceles trapezoid, kite, parallelogram, rectangle, rhombus, square, trapezoid, and triangle classification by sides and angles (acute, right, obtuse, equilateral, isosceles, scalene). Construction highlights: uses GeoGebra commands Sort, Element, If to sort side lengths and apply conditional logic; boolean objects like diagBisect, diagCongruent, diagPerpendicular detect diagonal properties; opp1Parallel and opp2Parallel check opposite side parallelism; lengthA, lengthB, lengthC and related variables feed classification text. Suitable for middle and high school geometry, helping students visualize definitions and theorems, and serving as an interactive exploration tool.