14. Get the height of isosceles triangle

In the isosceles triangle \(ABC\), what is the length of altitude drawn from the vertex \(A\) to \(BC\) if  \(AC = 85\) units and the measure of unequal base \(BC = 154\) units?

 

 

 The length of altitude drawn from the vertex \(A\) to \(BC\) is  units.