Vectorial form:
3.6 m east => 3i
6.0 north => 6 j
Final position = 3.6i + 6j
Magnitude = √[ (3.6)^2 + 6^2] = √[12.96 + 36] = √48.96 = 7.0 m
Direction => arc tan (6/3.6) = arc tan (1.67) = 59.0 °
Answer: the dog is at 7.0 m, 59.0° to the north of the east from the starting point.