Explanation:

The Pythagorean Theorem: The sum of the areas of the two squares
on the legs (a and b) equals the area of the square on the
hypotenuse (c).
In mathematics, the Pythagorean Theorem or Pythagoras'
Theorem is a relation in Euclidean Geometry among the three sides of a
right triangle (right-angled triangle). In terms of areas, it states:
In
any right triangle, the area of the square whose side is the hypotenuse (the
side opposite the right angle) is equal to the sum of the areas of the squares
whose sides are the two legs (the two sides that meet at a right angle).
The theorem can be written as an equation
relating the lengths of the sides a, b and c,
often called the Pythagorean equation:

where c represents the
length of the hypotenuse, and a and b represent
the lengths of the other two sides. (Our solved example in
mathguru.com uses this concept)
http://en.wikipedia.org/wiki/Pythagorean_theorem
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