The proof to explain what the Pythagorean theorem means is:
Sum of areas of two smaller squares is equal to sum of area of larger square
Pythagoras Theorem
Pythagoras Theorem is defined as the way in which you can find the missing length of a right angled triangle.
The triangle has three sides, the hypotenuse (which is always the longest), Opposite (which doesn't touch the hypotenuse) and the adjacent (which is between the opposite and the hypotenuse).
Pythagoras is in the form of;
a² + b² = c²
In this case, we see that:
The number of squares at the base of the triangle is 9 while the number of squares perpendicular to the base of the triangle is 16.
The number of squares at the hypotenuse is 25
Thus, we see clearly that:
Sum of areas of two smaller squares is equal to sum of area of larger square