My first proof was the Euclid’s proof. In this proof, I proved that given any right triangle, and square opposite, the right angle is always equal to the sum of the other two squares. To begin this proof, you start with the triangle ABC with angle BAC congruent to a right angle. It is proven that on any line we can always construct a square. Therefore, we construct a square on line BC and on line AB and line AC we construct two other squares. It is said that with any line and any point we can always construct a parallel line through the given point.