In Fig. 4.145, If and , prove that .

Given ABBC, DC BC and DE AC


To prove:- ΔCED ~ΔABC


Proof:-


<BAC + <BCA = 90° …………..(i) (By angle sum property)


And, <BCA + <ECD = 90°……(ii) (DC BC given)


Compare equation (i) and (ii)


<BAC = <ECD……………..(iii)


In ΔCED and ΔABC


<CED = <ABC (Each 90°)


<ECD = <BAC (From equation iii)


Then, ΔCED ~ΔABC.


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