Calculation example – Calculate the height of a building - 2

Calculate the height of a building where the ground is sloping up or down from the observer.

Known values: Height h of the observer, horizontal distance d, vertical angle θ, ground slope angle α.

Solution: Height of the building H+h.

First, measure horizontal distance d, vertical angle θ, and ground slope angle α from observer point A.

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.