I am a regular closed polygon whose interior angles each measure exactly 135 degrees. How many sides do I have?
8
The formula for each interior angle of a regular n-gon is (n - 2) × 180 / n. Setting this equal to 135 gives (n - 2) × 180 = 135n, which solves to 45n = 360, so n = 8 (an octagon).
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: Hard. More like this: Math riddles with answers or try Target 24 for a different kind of puzzle.
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