# How do you find the length of the diagonal of the cookie sheet if Maria has a rectangular cookie sheet that measures 10 inches by 14 inches?

Nov 22, 2014

Use the pythagorean theorem.
Treat your diagonal as the hypotenuse.

${a}^{2} + {b}^{2} = {c}^{2}$

$\implies {10}^{2} + {14}^{2} = {c}^{2}$

$\implies 100 + 196 = {c}^{2}$

$\implies 396 = {c}^{2}$

$\implies c = \sqrt{36 \cdot 11}$

$\implies c = 6 \sqrt{11}$