Answer:
Step-by-step explanation:
I'm from the UK and I'm not familiar with a two column proof, but the following proves the converse.
Draw 2 right angled triangles with the 2 legs = a and b in each case and the longest side = c in one triangle and f in the other.
By Pythagoras a^2 + b^2 = c^2 (Given)
Also in the other triangle a^2 + b^2 = f^2, if it is right-angled.
Therefore a^2 = f^2 and a = f.
So the 2 triangles are congruent by SSS.
So m < C in one triangle = m < F ( the angles opposite the hypotenuse)
Therefore the second triangle is right angled .
This completes the proof.
