Answer:
The answer to your question is: (3, 0)
Step-by-step explanation:
Data
Origin (0, 0)
Point (3, 7)
Then, from the information given, we can conclude that 3 is the adjacent leg and 7 is the opposite leg.
Formula
           c² = a² + b²
            c² = 3² + 7²
           c² = 9 + 49
           c² = 58
           c = √ 58
The coordinates of the vertex where the legs of the right triangle meet must be (3, 0)