Proving the Pythagorean Theorem with Starburst and graph paper:
1)
Introduce the Pythagorean Theorem, a2 + b2 = c2. Be sure that students know that this works
with only right triangles.
2) Review the names of the sides of the right triangle (legs and hypotenuse.) Help students
understand that the “c” in the Pythagorean Theorem always refers to the hypotenuse.
3) Watch the youtube video “Emma Pythagorean Theorem Proof”
http://www.youtube.com/watch?v=uOTs2ck1_jU
a)
b)
c)
d)
Draw a right triangle with the legs the length of 3 starburst and 4 starburst.
Create the squares of each leg using starburst.
Create the square of the hypotenuse by using starburst.
Lay the starburst from the squares of the legs on top of the starburst of the square of the
hypotenuse. They will equal. In doing so, you have proven that a2 + b2 = c2
4) Using graph paper, draw a right triangle with the legs 3 and 4.
Draw the square off of each leg, representing 32 and 42.
8.G.6 Handout #2
Next draw the square representing c2
Cut out the “9 square” and the “16 square” and see if you can fill the “c2 square.”
If the “9 square” and “16 square” filled the “c2 square”, we can say that 9 + 16 = c2. So, we can write the
equation 25 = c2. We can then take the square root of each side and find that c = 5. So, the triangle with
the legs of 3 and 4 and a hypotenuse of 5 creates a right triangle.
8.G.6 Handout #2