Your sketch should have three linear pieces.
The domain is given by the piecewise function above.
The range can be seen on the graph. What is the highest and lowest y-value? Are there any holes or jumps on that interval?
We know that the graph has a starting point (0,0) so, it could only be continuous when x > 0.
Be mindful of the 3 conditions of continuity:
Area = k(base)(height), where k is some constant. The base is determined by the units on the x-axis. The height is determined by the units on the y-axis. Multiply.