Brain Blow Level 12

Overview

A geometric figure built from a pentagon and crossing diagonals fills the middle of the board, and the prompt asks how many triangles there are. A number input field and an Ok button sit below the drawing. The visible outline hides smaller triangles formed where the diagonals cross, so the answer is counted from the complete arrangement rather than from the obvious large shapes. The total number of triangles in the figure is 8, and this value is entered into the field and confirmed with Ok.

• Difficulty: Regular
• Estimated moves: 2

Step-by-Step Solution

1. Study the outer pentagon and the lines crossing inside it, following each diagonal from one corner to the other. Identify the large triangles first, then look for the smaller triangles bounded by segments of those same lines.

1. Count every closed triangle formed by the drawn segments, including small ones nestled between crossings, and avoid counting shapes that need an extra line that is not actually present. Working corner by corner brings the total to 8.

1. Enter the total 8 into the number field below the figure, adjusting the digits until that value appears. The puzzle accepts the triangle count as a plain number, not a shape selection, so no figure on the board needs to be tapped.

1. Press Ok to submit the total. The level completes when the entered count matches the number of triangles in the arrangement; a rejected count means a triangle was missed or a non-triangle was counted.

1. If your first count feels low, trace each diagonal a second time and mark off triangles as you find them, because small wedges between adjacent crossings are easy to skip on one pass. Remember that the count includes only closed shapes whose three sides are drawn; a four-sided region or an open wedge should not be added to the total. After reaching the count of 8, re-enter it on the field and press Ok, and if the number is rejected, look again at the innermost small triangles rather than changing the large outer ones.

Strategy & Reasoning

Counting puzzles reward systematic inspection over a quick glance. The obvious large triangles are easy to spot, but the intersections create additional small triangles between adjacent lines, and those small pieces are what makes the total higher than a first look suggests. Working around the figure corner by corner keeps the count consistent.

A shape counts only if all three of its sides are segments of the drawn lines; a region that would require an invisible edge should not be added. Once the count matches the level's expected total of 8, the Ok button confirms it. There are no hidden objects to drag out here, just the lines already drawn on the board.

Tips & Common Mistakes

• Do not count only the big outer triangles; small triangles between the diagonal crossings also count toward the total.
• Skip any region that needs an imaginary side to close it; only triangles fully bounded by drawn segments should be counted.
• Recheck the corners and intersections if your number is rejected, since a missed small triangle is the most common off-by-one error.