Think you can spot every triangle at a glance? This classic brain teaser hides more shapes than you expect—let’s break it down level by level and tally them all.
We can see that the main shape is a large triangle divided by horizontal and vertical lines:
- There are 3 horizontal lines dividing the large triangle into 4 levels.
- There are 2 vertical lines, which divide each level into 3 parts (creating multiple smaller triangles).
- Overall, the shape contains many small triangles, both individual and combinations of smaller ones.
Counting:
Level 1 (top):
- 1 small triangle.
Level 2:
- 2 small triangles (left and right).
- Plus 1 larger triangle formed by combining the whole level → 3 triangles in total.
Level 3:
- 3 small triangles (left, center, right).
- 2 medium triangles formed by combining two small ones.
- 1 large triangle from the entire level → 6 triangles in total.
Level 4 (bottom):
- 3 small triangles.
- 3 medium triangles (each combining two small ones).
- 1 large triangle from the full level → 7 triangles in total.
Total triangles from each level:
- Level 1: 1
- Level 2: 3
- Level 3: 6
- Level 4: 7
Additionally, triangles formed by combining multiple levels:
- Level 1 + 2: 1
- Level 2 + 3: 2
- Level 3 + 4: 3
- Level 1 to 3: 1
- Level 2 to 4: 1
- Whole large triangle: 1
Total combined triangles: 9
Final Total:
1 (level 1) + 3 (level 2) + 6 (level 3) + 7 (level 4) + 9 (combinations) = 26 triangles
✅ Answer: 26 triangles
