Add the two smallest numbers together. If this sum is greater than the third, or largest number, the three numbers can represent a triangle. Otherwise they cannot. I will do 1 and 3. 1. 3,4,5. The two smaller numbers are 3 and 4. Their sum is 3+4=7. 7 is more than 5, which is the third, or largest number, so they represent a triangle. 3. 5,5,10 The two smaller numbers are 5 and 5. Their sum is 5+5=10. 10 is NOT more than 10, which is the third, or largest number, so they DO NOT represent a triangle. This is very easy, So you do the others. Edwin