Area Calculator Rectangle Triangle Circle Trapezoid Parallelogram Ellipse Circle Se...
Area Calculator
Rectangle Area
Length (units)
Width (units)
Triangle Area
Base (units)
Height (units)
Circle Area
Radius (units)
Trapezoid Area
Base 1 (units)
Base 2 (units)
Height (units)
Parallelogram Area
Base (units)
Height (units)
Ellipse Area
Semi-Major Axis (units)
Semi-Minor Axis (units)
Circle Sector Area
Radius (units)
Central Angle (degrees)
Regular Polygon Area
Number of Sides
Side Length (units)
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Results
Rectangle
Triangle
Circle
Trapezoid
Parallelogram
Ellipse
Circle Sector
Regular Hexagon
Understanding Area Calculations
Area calculations are fundamental in mathematics, engineering, architecture, and everyday life. Whether you're calculating the amount of paint needed for a wall, determining land area for construction, or solving geometry problems, understanding how to calculate the area of different shapes is essential.
Rectangles and parallelograms use the simple base × height formula. Triangles require half of that since they're essentially half of a parallelogram. Circles and ellipses involve the mathematical constant π (pi) and their respective radii or axes.
Trapezoids average the two parallel bases before multiplying by height. Circle sectors calculate a fraction of the full circle based on the central angle. Regular polygons use trigonometric functions to break the shape into triangles radiating from the center.
Use these calculators to quickly find the area of any shape and understand the underlying mathematical principles that govern geometric area calculations.
Frequently Asked Questions
A: Area measures the space inside a shape (square units), while perimeter measures the distance around the outside (linear units). For example, a rectangle with length 4 and width 3 has an area of 12 square units and a perimeter of 14 units.
A: A triangle is exactly half of a parallelogram (or rectangle) with the same base and height. If you take two identical triangles and put them together, they form a parallelogram, so each triangle has half the area.
A: Pi (π) is a mathematical constant approximately equal to 3.14159. It represents the ratio of a circle's circumference to its diameter. This constant appears in all circle-related formulas because it's fundamental to the geometry of circles.
A: For irregular shapes, break them down into regular shapes (rectangles, triangles, etc.), calculate each area separately, then add them together. Alternatively, you can use the shoelace formula if you know the coordinates of all vertices.
A: A circle is a special type of ellipse where both axes are equal. An ellipse has two different axes: the semi-major axis (longer) and semi-minor axis (shorter). When both axes are equal, the ellipse becomes a circle.
A: These calculations use precise mathematical formulas and are accurate to the limits of JavaScript's floating-point arithmetic. For practical purposes, they're accurate enough for engineering, construction, and academic applications.
A: No, these formulas are specifically for 2D (flat) shapes. For 3D shapes like cubes, spheres, or cylinders, you need volume formulas, which calculate the space inside the object rather than the area of a flat surface.