Sujikai Sudoku Puzzles - Expert 200 vol. 4

A Sujikai puzzle is constructed from 45 cells placed in a right-triangle as shown below. Some cells already contain a digit from 1 to 9. You must place a digit in each of the remaining empty cells to determine the unique solution that obeys three simple rules: No digit occurs twice in any horizontal row, vertical column or diagonal. No digit occurs twice in any of the three larger 3x3 square regions enclosed by thick borders. No digit occurs twice in any of the three larger triangular regions enclosed by thick borders.