Brain Out Level 172

Overview

Level 172 asks "How many triangles below?" It displays a large outer triangle subdivided by a horizontal crossbar, a vertical line running from the apex to the base, and a diagonal line through the lower-right area. Below the figure, a yellow minus arrow, a black counter, and a yellow plus arrow let you set a number, with Clear and OK buttons underneath. Most players count the triangles visible inside the drawing and arrive at 12, but the Brain Out trick is that the yellow minus and plus arrowheads themselves are triangles. Adding those two UI triangles gives the correct total of 14.

• Difficulty: Hard
• Estimated moves: 3

Step-by-Step Solution

1. Start by carefully counting every triangle inside the black-line figure. Trace each region and each combination of regions that forms a closed three-sided shape. Working methodically across small, medium, and large combinations, the subdivided outer triangle contains 12 triangles.
2. Resist the urge to tap OK at 12. The puzzle is not satisfied by the geometric drawing alone. Look at the controls directly beneath the figure.
3. Examine the yellow minus arrow on the left and the yellow plus arrow on the right. Each arrowhead is a solid filled triangle shape. They are part of the screen, and the question "how many triangles below" refers to everything below the prompt.
4. Add those two arrow triangles to your running total. 12 in the drawing plus 2 arrowheads equals 14.
5. Tap the yellow plus arrow repeatedly until the counter reads 14. If you pass 14, tap the yellow minus arrow to come back down.
6. With the counter set to 14, tap the blue OK button. The level-complete pop-up appears with the line "You are getting better and better!" Tap Next to continue.
7. This is the same triangle-counting drawing as level one sixty-eight; the twelve inner triangles plus the two on-screen arrows total fourteen. Enter fourteen as your answer.

Strategy & Reasoning

This puzzle is a counting trap built on wording. The geometric figure is deliberately dense enough that counting it correctly takes real focus, which makes you assume the question is only about that drawing. Brain Out redefines "below" to include the counter UI itself. The arrowheads are drawn as solid triangles rather than rounded buttons, which is the visual clue that they are meant to be counted.

Answering 12 fails because it ignores the two arrowheads. Answering higher than 14 also fails because there are no other triangle shapes on the screen. The Clear and OK buttons are rounded rectangles, the counter is a rounded oval, and the outer big triangle is already included in the 12 subdivision count. There is no separate bonus for counting the outer border twice.

The lesson this level teaches is the same one it repeats across the game: interface objects are fair game whenever the puzzle is a visual count. The reason the level appears again with the same figure is to confirm whether you have internalized that habit, rather than just memorizing the number. The congratulatory message "You are getting better and better" is the game saying you have started noticing UI triangles automatically.

Tips & Common Mistakes

• Stopping at 12 after counting only the figure. The two yellow arrow buttons below are themselves triangles and must be added.
• Splitting quadrilateral regions into triangles that do not exist. Only regions bounded entirely by straight black lines count; mixed shapes do not.
• Confirming with the counter at 12 or 13. The accepted value is exactly 14, so adjust with the plus and minus arrows before tapping OK.