Properties of Isosceles Triangles by Karen Handy

This GeoGebra example dynamically demonstrates the fundamental properties of isosceles triangles, including equal legs, equal base angles, and the coincidence of the angle bisector, median, and altitude from the apex. It covers core mathematical concepts such as the definition of isosceles triangles, axial symmetry, congruent triangles, the cosine rule, and the application of trigonometric functions to relate sides and angles. The construction uses the Circle command to create the triangle by drawing a circle centered at the apex to determine the equal sides, along with multiple text objects (text1 to text11) to label side lengths, angles, and relationships, and line segments (a, b, c, d, e, f, g, h, i, j, k) to connect key points. This resource is suitable for middle and high school students learning plane geometry, and serves as an interactive tool for teachers to demonstrate or for students to explore the properties of isosceles triangles.