Tuesday, February 21, 2017

The Final Problem -- Pythagorean Theorem

The fourth and final problem that students were challenged to solve during I Love Math season was this classic:




Demonstrating the
Pythagorean Theorem


You know what a right triangle is.  Right?

It has one right angle. 
(Could it have more than one?  That is worth thinking about for a minute.)

A right triangle always has one side that is longest.
The longest side is always across from the right angle.
It has a name:  hypotenuse.

The other two sides will always be shorter than the hypotenuse.
They always come together to “create” the right angle.

A long time ago, a mathematician named Pythagoras figured out that there is always a relationship between the lengths of the three sides of a right triangle.  We could measure the lengths of the two short sides and call those lengths a and b.  We could measure the length of the hypotenuse and call it c.

Here is the relationship:

a2 + b2 = c2

Pythagoras liked to picture things geometrically.  So the way he really thought about this formula was like this:  If I take the right triangle, and if I draw a square on each of the three sides, then the areas of the two smaller squares will always add up to equal the area of the big square.



Demonstrate the Pythagorean Theorem using the square and the triangles you were given.

If it helps to see another set of geometric figures, here is another set.  These are slightly different than the ones above, but they work just as well to demonstrate the theorem.  Enjoy!