Calculation of the area of a geometric figure.

Online area calculator which allows to calculate the area of a rectangle, square, triangle or circle.

The calculator is able to calculate the usual areas online. It can calculate the area of a rectangle, the area of a square, the area of a circle, the area of a triangle. The area calculator specifies the calculation steps to obtain the result.

Calculating the area of a rectangle

The area of a rectangle is given by the formula `(L*l)` where L represents the length and l the width a side. The area of a rectangle is equal to the product of its sides. The area calculator supports both numerical and literal expressions, the calculated length is returned in exact and approximate form.

Thus, the calculation of the area of a rectangle whose length is 3 and width is 2 is done by entering the following formula area(`3;2`).

Calculation of the area of a square

The area calculator is able to calculate the area of a square which is given by the formula `a^2` where a is the length of one side of the square. The calculated area is returned in exact and approximate form.

Thus, the calculation of the area of a square whose length of one side is 3 is done by entering the following formula area(`3`).

Calculation of the area of a circle

The area calculator is able to calculate the area of a circle, which is given by the formula `pi*r^2` where r is the radius of the circle. The calculated area is returned in exact and approximate form.

Thus, the calculation of the area of a circle of radius 3 is done by entering the following formula area(`3`).

Calculation of the area of a triangle

The area calculator is able to calculate the area of a triangle from its 3 sides using Heron's formula, which is written as follows: `S=sqrt(p*(p-a)*(p-b)*(p-c)`, where a, b, c represent the length of the sides of the triangle, and p is the half perimeter `p=(a+b+c)/2`. The calculated area is returned in exact and approximate form.

Thus, the calculation of the area of a triangle whose length of each side would be respectively equal to 5, 6 and 7 is done by entering the following formula area(`5;6;7`).

Games and quizzes on calculating the areas of common geometric figures

To apply the different calculation formulas, several quizzes on the calculation of the area of the square, the rectangle, and the circle are proposed.

Syntax :

• area(length;width) for a rectangle
• area(length) for a square
• area(length;length;length) for a triangle
• area(radius) for a circle

Examples :

• area(`3;2`) , returns 6
• area(`4`) , returns [16;`16pi`], 16 is the area of a square of length 4, and `16pi` is the area of a circle of radius 4.