Answer:
No, the sides do not satisfy the triangle.
Explanation:
OK, so you can use either use the Pythagorean Theorem or the 45-45-90 Triangle Theorem to find the answer to the question. I am going to use both in this explanation to help you see how they can be used.
Pythagorean Theorem:

45-45-90 Triangle Theorem:
a = b and
or

Use Pythagorean Theorem:
So
,
, and
.
?
(4×3) + (4×3) = 36 ?
12 + 12 ≠ 36
24 ≠ 36
Sides do not satisfy the triangle.
Use 45-45-90 Triangle Theorem:
?
? no
Sides do not satisfy the triangle.