- On the graph paper provided, mark the points (1,1), (1, 9), and (5,9). Connect them to make a right triangle. How do you know it is a right triangle?

- What is the area of this triangle? Explain how you found the area.

- Draw another right triangle, with vertices different from (1,1), (1,9), and (5,9). What is the area of your right triangle? Explain how you found the area.