Answer:
36
Step-by-step explanation:
Counting the squares: base = 12, height = 9.
We will use pythagorean theorem to find the third side.
Let it be x.
So,
[tex]x^2 = 12^2 + 9^2\\x^2 = 144 + 8 1 = 225\\x = 15[/tex]
Perimeter of triangle = sum lengths of all sides
= 12 + 9 + 15
= 36 units
