This is a collection of challenging numerical puzzles which are not easy to find, known as TRIGONS. Trigons are NOT SUDOKU. Your goal is to fill in each triangle so that the digits on the sides of the triangle add up to the sum given in the center of the triangle. Possible sum combinations are listed below each grid. Solving these puzzles will certainly sharpen your mind, but before that, make sure to sharpen your pencils! Are you ready?