Draw a triangle on a piece of paper, and cut it out.
Can you find a way to cut your triangle into no more than four pieces, and reassemble the pieces to make a rectangle?
Is it always possible, no matter what triangle you start with?
If you don't know where to start, click below to see some prompts that may help you:
First prompt:
Start with an isosceles triangle. How could you make it into a rectangle?
Is there a relationship between the base and height of your triangle, and the base and height of the rectangle?
Second prompt:
Draw any triangle, find the midpoints of two of the sides, and join them together. What do you notice?
Third prompt:
Once you have joined the midpoints, can you rearrange the pieces to make a parallelogram? Does that help you to create a rectangle?