and square root the answer to get the length of c, the hypotenuse/diagonal.......
pythagorean theorem! a^2 + b^2 = c^2. a and b are the legs (length and width). so plug those into the equation. Find the sum of that, and square root the answer to get the length of c, the hypotenuse/diagonal.
keywords: and,of,find,is,given,would,How,diagonal,exact,length,width,the,How would I find the exact length of the diagonal given the length is 8 and the width is 4