Area & Perimeter Explorer
Drag sliders to resize rectangles, circles, triangles and more — see area and perimeter formulas update live with every change.
Frequently Asked Questions
What is the difference between area and perimeter?
Perimeter is the total distance around the outside edge of a shape. Area is the amount of space inside the shape. Think of perimeter as the length of a fence and area as the grass it encloses.
How do you find the area of a circle?
Use the formula A = π × r², where r is the radius (the distance from the centre to the edge). For example, a circle with radius 5 m has area π × 25 ≈ 78.5 square metres.
Why are area and perimeter important in real life?
Area tells you how much paint, carpet, or tiles you need for a surface. Perimeter tells you how much fencing, trim, or border you need around an edge. Both show up in construction, design, and everyday projects.
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