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| 
 Hi Paula, I can help you get started. I drew a cross-section of the silo. 
 B is the midpoint of the face that rests against the side of the barn and hence the length of AB is 5 feet. I see two facts that come from the diagram. Since the |AB| = |BC| the angle BCA has measure 45o. Since triangle ABC is a right triangle you can use Pythagoras theorem to find the length |CA| which is the radius r of the circular base of the silo. I hope this helps,  | ||||||||||||
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