Atriangle has side lengths of 7 in., 9 in., and 11 in. determine whether this is a right triangle and why.

Not a right triangle.  See below for my reasoning.

Step-by-step explanation:

If this is a right triangle, then the sum of the squares of the two shorter sides will equal the square of the longest side:  7^2 + 9^2 = 11^2 => 49 + 81 = 121   But this is false.

Sorry about the other person that commented for points- I'll try to explain best  I can, please let me know if you have any questions as I am not great at explaining.

1- 14 because I assume "After he left the school" means this does not include the 6 miles to the library so to get back home he would have to travel another six miles west and 8 miles south. 8+6= 14 if you did include the other 6 then that would =20 but that isn't an option so...

2-  not sure? sorry hun but what i'm getting isn't an option

3- 40 minutes- 60 minutes/ 12 miles= 5 minutes per mile- 8miles*5minutes= 40 minutes

4-  not sure? sorry hun but what i'm getting isn't an option