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Puzzle #16

Detective IQ Club

By Subhadip Singha Oct 5, 2026

https://www.mindyourlogic.com/detective-iq-club/daily-puzzles/puzzle-16-find-the-number-of-triangles

Find the number of triangles

Find the number of triangles

A9 B11 C13 D17

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Answer and explanation

Answer: 13

<p><img src="/static/detective-iq-club/daily-puzzles/solution-1791269428957-5c8ed4cea83b.webp" alt="" title="solution" width="221" height="221"></p> <h3>Let’s Solve It Step by Step<br>Step 1: First, we have 9 small triangles — numbered 1 to 9.<br>Step 2: Some small triangles join together to make bigger triangles.<br>1 + 4 + 5 + 6 = Triangle 10<br>2 + 5 + 7 + 8 = Triangle 11<br>3 + 6 + 8 + 9 = Triangle 12<br>Step 3: All 9 small triangles together make the biggest triangle.<br>1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 = Triangle 13<br>Step 4: Now count them all.<br>9 small triangles + 4 bigger triangles = 13 triangles.<br>Correct Answer: C — 13</h3>

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