Answer:
The length of the hypotenuse of the isosceles right triangle with leg of length unit is:
√2 units.
Explanation:
Let a and b denote the leg of a right triangle and c denote the hypotenuse of the right triangle.
Now we apply the Pythagorean Theorem as:

Now as triangle is isosceles.
Hence, a=b=1 unit

Hence, the length of the hypotenuse is:
√2 units.