Question

In ∆ ABC , if angle ADE = angle B then prove that ∆ADE ~ ∆ABC
also if AD =7.2 cm BE=4.2cm & BC= 8.4cm then find DE

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pikachu

Answer 1

I trianglr ADE AND TRIANGLE ABC
Angle ADE = Angle ABC …… given
Angle EAD = angle BAC ...common angle
Therefore by AA test of congruency
Triangle ABC and ABD are similiar

Answer 2

In ABC & ADE,
angle A is common
angle ADE =angle ABC (GIVEN)
》ABC~ADE (by AA criteria)
》AB/AD=BC/DE=AC/AE