The images need to be rectified or else, yes, the lens distortion messes up the measurements. Really you just need a length and an angle to complete the triang

The images need to be rectified or else, yes, the lens distortion messes up the measurements. Really you just need a length and an angle to complete the triangle. The length is easy: measure distance from base of building to any point where you know the angle. But getting the angle from a point to the top of the building is tricky. I don’t know if any clever way to estimate that without stereo imagery. A lot of this stuff is automatically calculated when a digital surface model (DSM) is generated from stereo pairs of images. So you might be able to just look it up in Google Earth. This is the data (probably blended with many other sources such as LiDAR and ground survey data) Google uses to extrude buildings into 3D models. P.S. this was an assignment in 1st year for me. Estimate the height of the CN Tower from some aerial photos. I feel like I should remember more.