Answer:
36 units
Explanation:
The short leg is 9 units and the long one is 12 units.
Use pythagorean theorem to find the hypotenuse, a² + b² = c²
Plug in the numbers: 9² + 12² = c²
81 + 144 = c²
225 = c²
√225 = c
15 = c
Find perimeter by adding all 3 sides: 9 + 12 + 15 = 36 units.