Isosceles Trapezoid – Definitions and Construction

This GeoGebra worksheet demonstrates how to construct an isosceles trapezoid and explores its defining properties. The core concepts involved are the equality of the legs, the equality of the base angles, the parallelism of the two bases, and the symmetry axis that bisects the legs. Construction steps: create four points, connect them with segments to form a quadrilateral, draw two parallel lines to serve as the bases, ensure the non‑parallel sides (legs) are congruent, and optionally use the midpoint or reflection tool to draw the symmetry line and verify the base‑angle equality. The activity is suitable for middle‑school students learning about quadrilaterals, geometric construction, and proof‑based reasoning, as well as for teachers demonstrating properties of trapezoids.