If one angle of the triangle is 90°, then the triangle is a right triangle.
The side opposite to right angle is hypotenuse.
Let be the length of the third side of the triangle.
According to Pythagorean theorem, in a right triangle, square of the hypotenuse = sum of the squares of other two sides.
Applying Pythagorean theorem, 132 = 122 + 2
169 - 144 = 2
[Subtract 144 from both the sides.]
The length of the third side of the triangle is 5 units.
Correct Answer is : 5 units