Sources and verification

The reference: the app

The rules described on this site are those of the Triangles app, read from its code: allowed lines, counted triangles, end of the game, computer levels. When the app's built-in help and its code differ, the site follows the code.

Sources consulted

• Dots and boxes (new tab) (Wikipedia): the family of pencil-and-paper games in which you connect dots to close shapes, of which Triangles is a variant.
• Planar graph (new tab) (Wikipedia): why lines that never cross limit the number of possible lines and triangles on a board.
• Minimax algorithm (new tab) (Wikipedia): the search method behind the computer's Medium and Hard levels (Modes and grids page).

Links checked on October 30, 2026.

How the examples are verified

Before each publication, two independent programs redo all of the site's calculations:

• a tool connected to the app's engine, without modifying it, replays each example: the app accepts or rejects each line, counts the triangles and decides when the game ends;
• the same tool has the app's computer play against itself for the 2 complete games;
• it rereads the app's grids: 3 per device, up to 180 stars;
• a second, separately written program replays each line, recalculates each triangle and each score, and blocks publication at the slightest discrepancy.

Found a mistake? Write to us through the contact page.