Drawing is a welcome relief from the intellectually intense input of a math lesson. Turn a break into reinforcement by having students draw the meaning of a^2 + b^2 = c^2. Model an example for them by drawing a right triangle on the board. then draw a square extending from each side of the triangle. Use a ruler while you draw to demonstrate that you are using the exact lengths of the triangle's hypotenuse and sides to determine the size of your squares. Let groups and individuals choose from a box of right triangles to trace on paper. From there, they can race to see who completes the squares first.
After collecting their work, use some of the better drawn squares and triangles as the basis for a follow-up game for the next day. Cut the squares surrounding each triangle into smaller squares that are determined by the length of the sides. A square with 3-inch sides would divide into nine small squares. Keep the tiny squares in a container with the triangle upon which they were based. Pass them out to groups and ask them to recompose the squares on the sides of the triangles.
Make three squares whose sides correspond to the two sides and hypotenuse of an imaginary right triangle. Then make multiple copies of these squares but keep them in sets. Pass out the sets to groups in class and ask them to make a triangle with them. Award points to the first students who form a triangle with the empty space between properly joined squares.
Because the ancient Greeks learned through discussing their thoughts, the students should try this. It is also a good way to move away from concrete work into more abstract understanding. Start by mentioning the sides of a right triangle with short sides whose squares add up to an easy number -- whose root can be determined easily. Sides of 3 and 4, for instance, signify a hypotenuse of 5. Students should remember that from the lessons. Slowly make the triangles more difficult. Give them a hypotenuse and ask them to determine all the possible sides that would make that hypotenuse possible. Finally, have students suggest their own as challenges to one another.