Answer:
30 square units.
Explanation:
Divide the full polygon into two halves. The left half is 5 wide by 5 tall, making the area of the left 25 square units. The right half is 4 wide by 5 tall, and is perfectly cut in half. We can calculate the area normally, and then cut it in half: (5×4)/2 = 10 square units. Add the two polygons together, totalling 30 square units.