a^2+b^2 = c^2
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).
A 3,4,5 triangle has a right angle in it
check if the areas are the same:32 + 42 = 52
Calculating this becomes:9 + 16 = 25