## Intermediate Algebra (6th Edition)

$\text{approximately }51.2\text{ }ft$
Let $x$ be the width of the pond at the crossing point. Using $a^2+b^2=c^2$ or the Pythagorean Theorem, then \begin{array}{l}\require{cancel} 40^2+x^2=65^2 .\end{array} Using the properties of equality, the equation above is equivalent to \begin{array}{l}\require{cancel} x^2=65^2-40^2 \\ x^2=4225-1600 \\ x^2=2625 .\end{array} Taking the square root of both sides, the equation above is equivalent to \begin{array}{l}\require{cancel} x=\sqrt{2625} \\ x\approx51.2 .\end{array} Hence, the width of the pond at the crossing point, $x,$ is $\text{approximately }51.2\text{ }ft .$