what was to be proven.

Everything is congruent to itself. I'll put this as step three.Ta dah! You've just proven that all three sides of the left triangle are congruent to all three sides of the right triangle.Plus, the two triangles are congruent because of the side-side-side congruence theorem for triangles.When finished with a proof,I like to do what Euclid did.He marked the end of a proof with the letters QED.It's Latin for quod erat demonstrandum,which translates literally to what was to be proven.But I just think of it as ook what I just did!I can hear what you're thinking:why should I study proofs?