Question 1136650
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Make a sketch and find there a right angled triangle.


Then apply the Pythagorean theorem.


The radius of a metal circle = {{{sqrt(5^2 - 4^2)}}} = {{{sqrt(25-16)}}} = {{{sqrt(9)}}} = 3 feet.    <U>ANSWER</U>
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It recalls you a (3-4-5) right angled triangle.