Attached the solution with work shown.
Answer: 15 centimeters
Step-by-step explanation: You cut the rectangle into two triangles following the diagonal. You add 12 squared (144) and 9 squared (81) together. You get 225. You get the square root of 225 which is 15 and that is your answer. Basic solving for the hypotenuse.
9) They traveled 31.9 hours over the 3-day trip.
10.9 + 8.6 + 12.4 = 31.9
10) She does not have enough money. She has $12, but everything she wants to purchase would cost $12.39.
Large drink = 1.79
Turkey sandwich = 4.85
1.79 + 4.85 = 6.64
6.64 + 5.75 = 12.39