You want to draw a circle with a 4 inch radius. A trivial task for you and your trusty compass. When you go to grab your compass which has not had much love for a while you find it is rusted shut; stuck at 5 inches. Is it still possible to complete the task and draw a perfect circle with a 4-inch radius using the compass that can only draw circles with a 5-inch radius?
You may use other things as well to solve the problem such as a straightedge.