Answer:
55.36 m
Explanation:
The Pythagorean theorem relates the side lengths of a right triangle. For legs 'a' and 'b', and hypotenuse 'c', it tells you ...
c² = a² +b²
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For this figure, that means ...
?² = 19² +52² = 361 +2704 = 3065
? = √3065 ≈ 55.36 . . . . meters
The missing side length is about 55.36 meters.