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Geometry Formulas & Calculators

Understand geometry formulas with explanations, examples and interactive tools.

Geometry

Rectangle Perimeter

\(P=2(l+b)\)

Distance around a rectangle.

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Geometry

Square Perimeter

\(P=4a\)

Four equal sides of a square.

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Geometry

Rectangle Area

\(A=l\times b\)

Area enclosed by a rectangle.

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Geometry

Square Area

\(A=a^2\)

Area enclosed by a square.

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Geometry

Triangle Area

\(A=\frac12 bh\)

Half the product of base and perpendicular height.

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Geometry

Parallelogram Area

\(A=bh\)

Base times perpendicular height.

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Geometry

Circle Circumference

\(C=2\pi r\)

Distance around a circle of radius r.

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Geometry

Circle Area

\(A=\pi r^2\)

Area inside a circle of radius r.

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Geometry

Cube Volume

\(V=a^3\)

Volume of a cube with side a.

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Geometry

Cuboid Volume

\(V=lbh\)

Volume of a rectangular box.

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Geometry

Cube Total Surface Area

\(S=6a^2\)

Six equal square faces.

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Geometry

Cuboid Total Surface Area

\(S=2(lb+bh+hl)\)

Sum of areas of six rectangular faces.

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Geometry

Trapezium Area

\(A=\frac12(a+b)h\)

Average of parallel sides times perpendicular height.

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Geometry

Rhombus Area

\(A=\frac12d_1d_2\)

Half product of diagonals.

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Geometry

Cylinder Volume

\(V=\pi r^2h\)

Circular base area times height.

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Geometry

Cylinder Curved Surface Area

\(CSA=2\pi rh\)

Area of curved part of a right circular cylinder.

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Geometry

Cone Volume

\(V=\frac13\pi r^2h\)

One third of matching cylinder volume.

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Geometry

Sphere Volume

\(V=\frac43\pi r^3\)

Volume of a sphere.

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Geometry

Sphere Surface Area

\(S=4\pi r^2\)

Surface area of a sphere.

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Geometry

Pythagoras Theorem

\(a^2+b^2=c^2\)

Right triangle legs a,b and hypotenuse c.

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Geometry

Heron Formula

\(A=\sqrt{s(s-a)(s-b)(s-c)}\)

Triangle area from sides; s=(a+b+c)/2.

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Geometry

Sector Area

\(A=\frac{\theta}{360}\pi r^2\)

Area of circular sector for angle θ in degrees.

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Geometry

Arc Length

\(s=\frac{\theta}{360}2\pi r\)

Arc length for central angle θ in degrees.

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