# What is the length of the diagonal of a 10cm by 15cm rectangle?

Oct 13, 2015

The diaginal has $5 \sqrt{13}$ cm.

#### Explanation:

After using Pytagoras Theorem you get:

${d}^{2} = {10}^{2} + {15}^{2}$

${d}^{2} = 100 + 225$

${d}^{2} = 325$

${d}^{2} = 25 \cdot 13$

$d = 5 \sqrt{13}$