Prepare some sticks, cut them according to the given measurements, then determine which of the given sets will form a triangle, paste your output on a short bond paper and write if it forms a triangle or not.
1) 12, 8, 6 2) 4, 9, 21 3) 9, 15, 17 4) 3, 8, 10 5) 5, 10, 15