Here,
AO is an object , XY be the lens, CD and BD are refracted light, ID is an image.
InΔ OCA, AND ΔCID
∠ACO = ∠DCI because opposite angles ,
∠AOC = ∠DIC because both are 90° with the axis
∠OAC = ∠IDC remaining angle of triangle
Thus, ΔOCA and ΔCID are congruent
Therefore, Δ OCA and Δ CID are congruent
Therefore, \(\frac{CI}{CO}=\frac{ID\;}{OA}\)
\(\frac{image\;of\;dis\tan ce\;(v)}{image\;of\;dis\tan ce\;(u)\;}=\frac{height\;of\;image\;(I)\;\;}{height\;of\;object\;(O)\;}\)
= magnification
Hence proved.