Due to sun, a 6ft man casts a shadow of 4ft, whereas a pole next to the man casts a shadow of 36ft. What is the height of the pole?

Both the man and pole are near each other and are illuminated by same sun from same direction.

So angle of elevation for sun is same for both.
So ration of object to shadow will be same for all objects. (Proportionality Rule)
$$\frac{{{\text{Object}}\,{\text{height}}}}{{{\text{Shadow}}\,{\text{length}}}} = \frac{6}{4} = \frac{{\text{H}}}{{36}}$$
∴ H = 54 ft = Height of pole