What is the diagonal of a rectangle?

A diagonal is a straight line that connects one corner of a rectangle to the opposite corner. A rectangle has two diagonals, and each is the same length. read more

Each one is a line segment drawn between the opposite vertices (corners) of the rectangle. The diagonals have the following properties: The two diagonals are congruent (same length). In the figure above, click 'show both diagonals', then drag the orange dot at any vertex of the rectangle and convince yourself this is so. read more

The diagonal of the rectangle is equivalent to finding the length of the hypotenuse of a right triangle with sides 3 and 4. Using the Pythagorean Theorem: Therefore the diagonal of the rectangle is 5 feet. read more

You use the Pythagorean Theorem because a diagonal of a rectangle cuts the rectangle into two congruent right triangles. The length and width of the rectangle are the side lengths of the triangle; the diagonal is the hypotenuse of the triangle. read more