Answer
Refer to the graph below.
Work Step by Step
The graph of $x \ge 1$ is the region to the right of the vertical line $x=1$, including the line itself.
The graph of $y\lt3$ is the region below the horizontal line $y=3$.
Thus, the region represented by the given set is the region to the right of the vertical line $x=1$ (including the line itself) and below the horizontal line $y=3$.
Refer to the attached image in the answer part above for the graph.