Which sides are 'a' and 'b'?

They are the two parallel sides of the trapezoid; height is the perpendicular distance between them, not the length of the slanted sides.

Trapezoid Area Calculator

Calculate the area of a trapezoid given the lengths of its two parallel sides and the perpendicular height between them.

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Formula

Area = ((a + b) / 2) × h

Trapezoid Area and Number Sequences Explained

The trapezoid area formula and the arithmetic vs. geometric sequence formulas, worked through with real examples.

Triangle Area Calculator

Calculate a triangle's area from three side lengths using Heron's formula.

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Calculate the area, perimeter, and diagonal of a rectangle.

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Calculate the percentage increase or decrease between two values.

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Solve ax² + bx + c = 0 for real roots using the quadratic formula.

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Calculate the average of up to 10 numbers.