Sara is building a triangular pen for her pet rabbit. If two of the sides measure 8 feet and 15 feet, the length of the third side could be 1) 13 ft
2) 7 ft
3) 3 ft
4) 23 ft

1) 13 ft

Step-by-step explanation:

1) 13+8=21 which is greater than 15. Would be a triangle.

2) 7+8=15   This would be a single line, not a triangle.

3) 3+8<15   This would be a single line, not a triangle.

2) 15+8=23   This would be a single line, not a triangle.

but which class are u may know that first