Say you want to measure height of a Tall Tower, there are several techniques you can use. You will need measuring tape, a protractor and some scotch tape. Hehehehe Ohhh sorry I forgot you are here for a easy DIY(Do-it-yourself). So you will just need a android phone and Smart Measure – rangefinder.
This android app measures the distance and height of an object by using trigonometry. The effective distance is 1-50 meters.
Height of object = distance from object * tan(angle)
How to use SmartMeasure?