Answer:
One
Step-by-step explanation:
First, we need to check a triangle with these sides is possible. Since 4 plus 5 is 9, and 9 is less than 10, we can make a triangle with these sides.
To answer the question, we can only make one unique triangle. Why? They give us three lengths and a triangle has three sides.
However, if they are counting a triangle in different positions the answer will be greater. Since it would just be the same triangle, I am going with the answer of only one.