What is the diagonal distance across a rectangular piece of steel that measures 3 feet high and 4 feet wide?

What is the diagonal distance across a rectangular piece of steel that measures 3 feet high and 4 feet wide?

• A. 4 feet
• B. 5 feet
• C. 7 feet
• D. 3 feet

Answer: (B)

The diagonal of a rectangle is found using the Pythagorean theorem. Treat the height and width as the two legs of a right triangle, and the diagonal you’re after as the hypotenuse. Compute sqrt(3^2 + 4^2) = sqrt(9 + 16) = sqrt(25) = 5 feet. So the diagonal distance is 5 feet. The other numbers would correspond to just the height or the width, or aren’t possible for these dimensions, so they don’t fit the diagonal in this case.

The diagonal of a rectangle is found using the Pythagorean theorem. Treat the height and width as the two legs of a right triangle, and the diagonal you’re after as the hypotenuse. Compute sqrt(3^2 + 4^2) = sqrt(9 + 16) = sqrt(25) = 5 feet. So the diagonal distance is 5 feet. The other numbers would correspond to just the height or the width, or aren’t possible for these dimensions, so they don’t fit the diagonal in this case.