Engineering Board Exam Reviewer · Polygons · medium
A polygon has 54 diagonals. How many sides does it have?
- 9
- 10
- 12
- 15
Answer
C. 12
Solution
n(n-3)/2=54 n2-3n-108=0 (n-12)(n+9)=0, so n=12.
More Polygons questions
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