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Diagonals of a Square

A square has 2 diagonals. The point where they cross is called the center of symmetry. Here we learn how to count the diagonals and find their length.

Diagonals of a square

Number of Diagonals

Formula for Counting Diagonals

Use the general polygon diagonal formula for a shape with n sides:

Formula for number of diagonals of a square
Dnumber of diagonals 4number of sides of a square

Length of a Diagonal

Formula Using the Pythagorean Theorem

Each diagonal of a square forms a right triangle (with a 90° angle). We can use the Pythagorean theorem to find its length:

Squared diagonal formula
Square diagonal length formula
dlength of the diagonal llength of one side

More About the Square

Click on any element to learn more.

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