Flash and Math Angle of Elevation. Find the angle of elevation of your phone. Great introduction to a trigonometry lesson: Point the phone at the top of a tree and tap the screen. This will lock in place a measurement of the angle of elevation of your phone with the horizontal — combine this information with your distance from the base of the tree to find the height of the tree above your phone. This experimental app is part of a complete suite of precalculus apps coming soon. Source code for the "Angle of Elevation" app can be found at www.flashandmath.com.