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Answer:
The third side has a length of 9 units. Expressed as a radical that would be √81.
Step-by-step explanation:
This is an application of the Pythagorean theorem, which states that the square of the hypotenuse of a right triangle is equal to the sum of the squares of the other two sides.
With that in mind we can simply solve the third side as follows:
[tex]h^2 = l^2 + w^2\\l^2 = h^2 - w^2\\l = \sqrt{h^2 - w^2} \\l = \sqrt{41^2 - 40^2}\\l = \sqrt{1681 - 1600}\\l = \sqrt{81}\\l = 9[/tex]
So the remaining side has a length of 9.