Question
Find the diagonal $ d $ of a rectangle if side $a = 12\, \text{cm}$ and side $b = 18\, \text{cm}$.
Answer
$6 \sqrt{ 13 }\, \text{cm}$
Explanation
To find diagonal $ d $ use Pythagorean Theorem:
$$ a^2 + b^2 = d^2 $$After substituting $a = 12\, \text{cm}$ and $b = 18\, \text{cm}$ we have:
$$ \left( 12\, \text{cm} \right)^{2} + \left( 18\, \text{cm} \right)^{2} = d^2 $$ $$ 144\, \text{cm}^2 + 324\, \text{cm}^2 = d^2 $$ $$ d^2 = 468\, \text{cm}^2 $$ $$ d = \sqrt{ 468\, \text{cm}^2 } $$$$ d = 6 \sqrt{ 13 }\, \text{cm} $$This page was created using
Rectangle Calculator