What is the length of the hypotenuse? If necessary, round to the nearest tenth.

  75 mi

Step-by-step explanation:

The Pythagorean theorem tells you the square of the hypotenuse is the sum of the squares of the sides.

  c² = (45 mi)² +(60 mi)²

  c² = (2025 +3600) mi² = 5625 mi²

  c = (√5625) mi = 75 mi

The length of the hypotenuse is c = 75 miles.

Additional comment

The given side lengths have the ratio 60 : 45 = 4 : 3. That should tell you this is a 3:4:5 right triangle. The hypotenuse will be 5 times the scale factor of 15. It will be 5×15 = 75.