Consider △ABC with ∠B=90∘. The perpendicular from B to the hypotenuse AC meets AC at D.
(i) Prove that △ADB∼△ABC and △CDB∼△ABC.
(ii) Using the similarities established in part (i), derive the relations AD⋅AC=AB2 and DC⋅AC=BC2.
(iii) From the relations obtained in part (ii), deduce that AC2=AB2+BC2.