Q2 of 62 Page 186

The image of a man of height 1.8 m, is of length 1.5 cm on the film of a camera. If the film is 3 cm from the lens of the camera, how far is the man from the camera?

The figure is given below. Here, FE is the man whose height is 180 cm.

HG is the image of the man, height of image = 1.5 cm


AB is the camera lens.



We need to find the length of EO.


In ΔFEO and ΔHGO


∠GOH = ∠FOE (Vertically Opposite)


∠GHO = ∠FEO by alternate angles (FE∥GH)


∴ ΔFEO ∼ ΔHGO


(∵ ΔFEO ∼ Δ HGO)



⇒ EO = 3.6 m


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