Consider ( ABC ) with ( B = 90^ )

MATHEMATICS · Multi-part · CBSE · Mathematics · Triangles · Triangles

Problem

Consider △ABC\triangle ABC with ∠B=90∘\angle B = 90^\circ. The perpendicular from BB to the hypotenuse ACAC meets ACAC at DD. (i) Prove that △ADB∼△ABC\triangle ADB \sim \triangle ABC and △CDB∼△ABC\triangle CDB \sim \triangle ABC. (ii) Using the similarities established in part (i), derive the relations AD⋅AC=AB2AD \cdot AC = AB^2 and DC⋅AC=BC2DC \cdot AC = BC^2. (iii) From the relations obtained in part (ii), deduce that AC2=AB2+BC2AC^2 = AB^2 + BC^2.

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