Question 822759
<pre>
1) 4,9,13

Those three numbers CANNOT be the sides of a triangle because 
the two smaller numbers, 4 and 9, must have a sum which is
strictly greater than the third number.  4+9=13 and 13 is NOT
strictly greater than the third number 13. 


 2) 5,8,12

Those three numbers CAN be the sides of a triangle because 
the two smaller numbers, 5 and 8, have a sum which is
strictly greater than the third number.  5+8=13 and 13
is greater than the third number 12.

 3) 5,5,13

Those three numbers CANNOT be the sides of a triangle because 
the two smaller numbers, 5 and 5, must have a sum which is
strictly greater than the third number.  5+5=10 and 10 is NOT
greater than the third number 13. 

 4) 5,5,10

Those three numbers CANNOT be the sides of a triangle because 
the two smaller numbers, 5 and 5, must have a sum which is
strictly greater than the third number.  5+5=10 and 10 is NOT
strictly greater than the third number 10. 

Edwin</pre>