- Volume Calculator
- Area Calculator
- Perimeter Calculator
- Surface Area Calculator
- Circle Calculator
- Rectangle Calculator
- Triangle Calculator
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Right Trapezoid Area CalculatorCalculate the area of a right trapezoid from its two parallel sides and height using Area = ((a+b)/2)·h. Fast, free, and accurate.
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Right Trapezoid CalculatorCalculate the area, slant leg, and perimeter of a right trapezoid from its two parallel sides and height. Free online geometry calculator.
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Trapezoid Height CalculatorFind the height of a trapezoid from its area and two parallel bases using h = 2A / (a + b). Free, instant, and accurate geometry calculator.
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Polygon Area and Perimeter from Coordinate Points CalculatorCompute the enclosed area and perimeter of any simple polygon from an ordered list of (x, y) coordinate vertices using the shoelace formula. Free and exact.
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Surface Area of a Rectangle CalculatorCalculate the surface area of a rectangle instantly. Enter length and width to get area (length × width) plus the perimeter. Free, fast and accurate.
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Square Inches of a Circle CalculatorCalculate the area of a circle in square inches from its radius or diameter using A = πr². Fast, accurate, and free circle area calculator.
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Square Footage of a Circle CalculatorFind the square footage (area in ft²) of a circle from its diameter or radius. Also shows circumference, square yards, and square meters.
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Square Feet of a Triangle CalculatorCalculate the area of a triangle in square feet from its base and height. Instantly converts to square yards and square meters too.
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Quarter Circle Area CalculatorCalculate the area of a quarter circle from its radius using A = πr²/4. Also returns the quarter arc length and full perimeter instantly.
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Isosceles Trapezoid Area CalculatorCalculate the area of an isosceles trapezoid from its two parallel bases and height using A = ((a + b) / 2) × h. Fast, free, and accurate.
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Isosceles Trapezoid CalculatorCalculate the area, leg length, and perimeter of an isosceles trapezoid from its two parallel bases and height. Fast, accurate geometry tool.
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Irregular Trapezoid Area CalculatorFind the area of a trapezoid (regular or irregular) from its two parallel sides a, b and height h using A = ((a+b)/2)·h. Fast and accurate.
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Heptagon CalculatorCalculate the area, perimeter, apothem and circumradius of a regular heptagon (7-sided polygon) from its side length. Fast, free and accurate.
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Elliptical Segment Area CalculatorCompute the segment area, chord length and elliptic arc length of an ellipse between two polar angles, given the semi-axes a and b. Free geometry calculator.
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Dodecagon Area CalculatorCalculate the area of a regular dodecagon (12-sided polygon) instantly from its side length using Area = 3(2+√3)a². Also shows the perimeter.
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Dodecagon CalculatorCalculate the area, perimeter, apothem and circumradius of a regular dodecagon (12-sided polygon) from its side length instantly.
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Ancient Roman Length ConverterConvert ancient Roman lengths (Roman mile, passus, Roman foot) into modern statute miles, feet, and meters using the standard 1479 m per Roman mile.
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Regular Polygon Side and Perimeter from AreaFind the side length and perimeter of a regular polygon from its area and number of sides. Free calculator using a = sqrt(4S·tan(pi/n)/n).
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Decagon CalculatorCalculate the area, perimeter, apothem and circumradius of a regular decagon (10-sided polygon) from its side length, with formulas and a worked example.
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Decagon Area CalculatorCalculate the area of a regular decagon (10-sided polygon) from its side length using the exact formula Area = (5/2)·s²/tan(π/10).
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Circumference and Area of a Circle CalculatorCalculate the circumference and area of a circle from its radius. Uses C = 2πr and A = πr². Instant results with diameter and worked formulas.
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Square in a Circle CalculatorFind the largest square that fits inside a circle. Enter the radius to get the inscribed square's side, diagonal, area, perimeter and fill ratio.
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Semicircle Area CalculatorCalculate the area and perimeter of a semicircle from its radius. Free online tool using A = πr²/2 with instant area, arc length and perimeter.
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Area of a Circle CalculatorCalculate the area of a circle instantly from its radius or diameter using A = πr². Also returns diameter and circumference. Free online geometry tool.
