Answer:
7 units
Explanation:
In an isosceles right triangle, the hypotenuse is √2 times the leg length. Then ...
... 7√2 = leg·√2
... 7 = leg . . . . . . . divide both sides by √2
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Comment on isosceles right triangle
If the legs are both length 1, the Pythagorean theorem tells us ...
... hypotenuse² = 1² +1² = 2
... hypotenuse = √2 . . . . . . . . . square root both sides of the equation
This result can be scaled by any multiplier you like. In this problem, the scale factor is 7, making the legs 7 and the hypotenuse 7√2.