The question is not completed
there is some numbers mising
Answer:
If you take the 2 smallest sides and put it in the pythagreon theorem to get the other side length.
Step-by-step explanation:
So if you have a triangle with side lengths, 3, 4, and 5, you can use the exact equation below.

Because this is true, then the triangle does have a right angle.
11 15 15/x
Jonah spent the cost of a movie ticket and split the cost of popcorn, so this needs to be represented by a " + ". Jonah just buy one piece tickets, so 11 is tickets price. We know Jonah's costs represented by the expression 11+15/x, "x" on behalf of the number of he and his friends, so 15 is the price of popcprn. 15/x means one person's money for the poopcorn, including Jonah.