In the given Fig. DEFG is a square and ∠BAC = 90°. Prove that
(i) ∆AGF ~ ∆DBG.
(ii) ∆AGF ~ ∆EFC.
(iii) ∆DBG ~ ∆AEFC
(iv) DE2 = BD × EC.
In the given Fig, PA, QB and RC are each perpendicular to AC. Prove that
In ∆CBQ and ∆CAP
∠BCQ = ∠ACP [common]
and ∠CBQ = ∠CAP = 90°
Therefore, by AA similar condition
In ∆ABQ and ∆ACR
∠BAQ = ∠CAR [common]
and ∠ABQ = ∠ACR = 90°
Therefore, by AA similar condition
...(ii)
Adding (i) and (ii), we get