Premise: "A construction worker works on a metal structure."
Hypothesis: "There is a construction worker building stuff."
Do we know that the hypothesis entailed by the premise? A step-by-step solution is:
A worker specified as being in construction is ordinarily involved in 'building stuff'; one who 'works on a structure' is even more likely to be 'building stuff'; 'a construction worker' establishes that there is a construction worker.
The final answer: yes.