** Known values: **Height

**of the observer, horizontal distance**

*h***, vertical angle**

*d***, ground slope angle**

*θ***.**

*α***Solution:** Height of the building ** H+h**.

First, measure horizontal distance ** d**, vertical angle

**, and ground slope angle**

*θ***from observer point A.**

*α*Calculate vertical distance * H*:

Calculate building height above the ground:

*Note that this method assumes that the horizontal distance can be measured from observer point.