A regular polygon has 54 diagonals. How many sides does it have?

Answer as guest — Start Free Practice Test to earn Practice PointsHow to earn pointsAsk a question+3Answer a question+1Someone answers yours+1Your Q gets upvoted+1Pioneer bonus (first 5)+51 point = ₹1 discount on purchases, ask questions & climb the leaderboard!

• A 54
• B 27
• C 9
• D 12

Submit Answer

Show answer and explanation

Answer: D. 12

x(x-3) / 2 =54 (x^2-3x)/2=54 x^2-3x=108 x^2-3x-108=0 x=-9 or 12. Hence, the answer is 12.

Answering after opening this box earns no Practice Points.