Pythagorean Theorem
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Transcript Pythagorean Theorem
Pythagorean Theorem
A quick visual proof
Consider the following square
a
b
b
c
c
a
c2
a
c
b
c b
a
There are four
congruent yellow right
triangles with sides a,
b and hypotenuse c.
Note that there are
four triangles and one
square
The square has side
length of c so its area
is c2
The sides of the
square have a length
of a+b
Now, consider this square
a
b
c
b2
b
a
a2
a
c
b
b
a
Note that this square
still has side lengths of
a+b and still has four
yellow triangles with
sides a and b and
hypotenuse c.
This time instead of
one square with area
c2, there are two
squares: one with area
a2 and one with area
b2.
To conclude
Both squares have the same side lengths
therefore, they have the same area.
Both squares have four congruent triangles
with sides a and b and hypotenuse c. So,
each region of the square containing these
triangles must have the same area.
If I subtract the area of the region
containing the triangles from the area of
the entire square, the two regions that are
left must have an equal area.
So, c2 = a2 + b2
Proof without words