Question

The diagonal of a rectangle is $15cm$. The width is $12cm$. What is the length of the rectangle?

Answer 1

Given that,

Digonal of a rectangle is $15cm$

Width $=12cm$

We know that,

$d=\sqrt{w^2+l^2}$

$l=\sqrt{d^2-w^2}$

$\begin{array}{c}d=\sqrt{{15}^2+{12}^2}\\ l=\sqrt{{15}^2-{12}^2}\\ =\sqrt{225-144}\\ =\sqrt{81}=9\end{array}$

Then,

We get the length of the rectangle is $9cm$.