Bhaskara’s Visual Proof of the Pythagorean Theorem

Figure 1

Bhaskara is famous for presenting the above figure and leaving only the exclamation, "Behold!"

In the figure 1, a square with side length c contains four right triangles with base b and height a, along with a smaller square in the center.
The total area on the left is therefore $c^2$.

On the right, the total area of the four right triangles is $4 \times \frac{a \times b}{2} = 2ab$ and the area of the smaller square is $(a - b)^2$.

Thus,
$c^2 = 2ab + (a - b)^2 = a^2 + b^2$ which proves the Pythagorean theorem.