Area of Circle Proof
Launch this tool in a distraction-free environment optimized for classroom instruction.
About
What is Area of Circle Pro?
Area of Circle Pro is a geometric sandbox that visually proves why the formula for the area of a circle is A = πr². By digitally slicing a circle into sectors and rearranging them, students can physically see how a curved shape transforms into a straight-edged parallelogram. The interactive canvases allow for a tangible, intuitive exploration of geometric proofs and limits.
Using it in class
This tool is specifically engineered for mathematics education, removing the abstract "magic" from formulas and replacing it with visual evidence.
Mathematics & Geometry
Demonstrate the concept of limits and approximation. As you increase the number of slices using the slider, the rearranged parallelogram's edges become straighter. Students can clearly see that the height of the shape equals the radius (r), and the combined arcs form the base, which is half the circumference (πr). Therefore, Base × Height = (πr) × (r) = πr².
Visual & Spatial Logic
Challenge spatial reasoning skills. Students can manually drag, flip, and snap the slices together to solve the puzzle of creating a rectangle out of a circle. The bright Cyan and Purple highlights on the arcs serve as a visual guide, proving that half the outer edge sits on top, and half sits on the bottom.