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Question

The perimeter of a rectangle is 56 meters. The ratio of its length to its width is 4:3. What is the length in meters of a diagonal of the rectangle?

Accepted Answer

Suppose that the rectangle's length is 4l, then it's width is 3l. Then its perimeter is 14l = 56, meaning that l = 4. Finally, the rectangle's diagonal is (4l)^2 + (3l)^2 = 5l = 20.