A goat is tethered by a 10-meter rope to an outside corner of a square barn measuring 10 meters on each side. The goat cannot step inside the barn. In terms of pi, over what exact area (in square meters) can the goat graze?
75π square meters
The barn occupies a 90-degree sector at the tether corner. The goat can freely sweep through the remaining 270 degrees (3/4 of a circle) with radius 10 meters. Because the rope length matches the side length of the barn, it cannot wrap around other corners to gain additional area. Thus, the grazing area is (3/4) * π * 10^2 = 75π square meters.
About this riddle
Math riddles hide a calculation inside a short story. Pull out the numbers, work out what is being asked, and watch for a trick such as a unit change.
Difficulty: Medium. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
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