A vertical stick of length 6 m casts a shadow 4 m long on the ground and at the same time a tower casts a shadow 28 m long. Find the height of the tower.

Let AB be a tower

CD be a stick , CD = 6m

Shadow of AB is BE = 28cm

Shadow of CD is DF = 4m

At same time light rays from sun will fail on tower and stick at the same angle

So, <DCF = <BAE

And <DFC = <BEA

< CDF = <ABE (Tower and stick are vertically to ground)

Therefore ΔABE ~ ΔCDF (By AAA similarity)

So, AB/CD = BE/DF

AB/6 = 28/4

AB/6 = 7

AB = 7 x 6

AB = 42 m

So, height of tower will be 42 meter.