Use the Pythagorean Theorem: \(a^2 + b^2 = c^2\)
You can do this because when you cut the rectangle in half with the diagonal, it forms a right triangle, making the diagonal the hypotenuse (c).
\(40^2 + 48^2 = c^2\)
\(1600 + 2304 = c^2\)
\(3904 = c^2\)
\(\sqrt{3904} = \sqrt{c^2}\)
\(62.48 = c\)
Diagonal: 62.48 inches
