12. Calculate the height of the embankment

A 28 \(m\) deep well with inner diameter 8 \(m\) is dug and the earth taken out is evenly spread all around the well to form an embankment of width 3 \(m\). Find the height of the embankment.

 

The height of the embankment \(=\) 10.3220.7717.8213.58 \(m\)