Online calculators

Our site contains more than 100 free online calculators on math, geometry and physics.

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Calculating the area of a rectangle online

Our online calculator allows you to calculate the area of a rectangle in two ways: through the length of its sides and through the diagonals. To find the area of a rectangle, select the appropriate way to enter the lengths of the sides and diagonals and the angle between them, and then click “To calculate”, the calculator will give the answer and the solution step by step!

Enter the data for calculating the area
Select the method of calculating the area:
The formula through the two sides:
a =
b =
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