Logic Masters Deutschland e.V.

A continuation of the Triangulation series.

If you've solved any other puzzle with similar rules before, the difficulty is probably less than 3/5.

Rules

• Normal Sudoku rules apply.
• Extend the given right angles to form isosceles triangles with the digit at the right angle being the number of cells occupied by each side of the respective triangle.
• Adjacent digits on a triangle sum to a triangular number (0,1,3,6,10,15,21,...).
• The sum of the digits in cells with right angles is not a triangular number.

Enjoy and thanks in advance for ratings and comments!