1. Plot a point near the upper right corner of a sheet of graph paper. Move your pencil 15 graph-paper units (squares) to the left and 20 units down, then plot another point. Use your ruler to measure the distance between the points. You should finish by converting your measurement to graph-paper units.

2. (Continuation) Square your answer (in graph-paper units), and compare
the result with the calculation 15² + 20².

3. (Continuation) Repeat the entire process, starting with a point near the
upper left corner, and use the instructions “20 squares to the right and 21
squares down.” You should find that the numbers in this problem again fit the equation a²+ b²= c² These are instances of the Pythagorean Theorem,
which is a statement about right-angled triangles. Write a clear statement of this useful result. You will need to refer to the longest side of a right triangle, which is called the hypotenuse.