Area of Circles, Rectangles, and Triangles

This example demonstrates how to calculate the area of circles, rectangles, and triangles. It involves core mathematical concepts such as area formulas, the circumference of a circle, the base and height of a triangle, and the opposite sides of a rectangle. Construction highlights include using GeoGebra commands to draw shapes, calculate areas, and dynamically adjust parameters to observe area changes. Suitable for middle school and above students to learn and understand basic geometric area calculation methods.