Answer:
15 in
Step-by-step explanation:
Using the formula d² = l² + w², we can substitute the numbers into their correct spots.
d x d = 9 x 9 + 12 x 12
d x d = 81 + 144
d x d = 225
Now we need to figure out what d is
15 x 15 = 225
So
15 squared = 9 squared + 12 squared
Meaning the answer is 15 in.
