Find the square root of $(272{)}^2-(128{)}^2$:

1. Let the expression inside the square root be $E=(272{)}^2-(128{)}^2$.2. Apply the difference of squares algebraic identity $a^2-b^2=(a-b)(a+b)$:
$$E=(272-128)(272+128)$$
$$E=144\times 400$$
Take the square root of $E$:
$$\sqrt{E}=\sqrt{144\times 400}=\sqrt{144}\times \sqrt{400}$$
$$\sqrt{E}=12\times 20=240$$