You would first use on the bottom of the box rectangle to find the diagonal CB =

The Pythagorean Theorem.

To find the length of the diagonal CB of a rectangle, you would need to use the Pythagorean theorem, which states that in a right triangle, the square of the hypotenuse (the side opposite the right angle) is equal to the sum of the squares of the other two sides.

In a rectangle, the diagonals form right angles with the sides of the rectangle. Let's assume the rectangle has sides AB and BC. The diagonal CB is the hypotenuse, while AB and BC are the other two sides of the right triangle.

Using the Pythagorean theorem formula, we have:

CB^2 = AB^2 + BC^2

To calculate the length of the diagonal CB, you need to know the lengths of the sides AB and BC. Once you have those measurements, you can substitute them into the formula and solve for CB.

Please provide the lengths of the sides AB and BC, and I can help you find the length of the diagonal CB.

To find the length of diagonal CB in a rectangle, you can use the Pythagorean theorem. Here are the steps:

Step 1: Identify the length and width of the rectangle.
Let's say the length of the rectangle is a units, and the width is b units.

Step 2: Square the values of the length and the width.
a^2 represents the square of the length, and b^2 represents the square of the width.

Step 3: Add the squared values of the length and the width.
a^2 + b^2 represents the sum of the squared values.

Step 4: Take the square root of the sum obtained in Step 3.
√(a^2 + b^2) gives the diagonal CB.

By following these steps, you will be able to calculate the length of diagonal CB in the rectangle.