12.5 Squash a Parallelogram

This example demonstrates how to squash a parallelogram through rotation and scaling operations, observing changes in its geometric properties. Core mathematical concepts include parallelograms, scalene triangles, matrix operations, circumcircle, and trigonometric functions (cosine and sine). Construction highlights involve using Rotate command for vertex rotation, Polygon command for shape creation, with objects like points A, B, α, B', a, b, C, D, q1, b', c, d, a_1, and text annotations. Suitable for high school students to learn geometric transformations, matrix applications, and the role of trigonometry in geometric problems.