Measuring Height of Object-Sun and Shadow-Similar Triangles

This app is used to exemplify how to indirectly calculate the height of an object out in the sun, using similar triangles principles. The idea is to measure 3 parameters: the shadow of the object, and the height and the shadow of another object (could be a person) out in the sun at the same point of time. Because of the movement of the sun in the sky, it is important to measure at the same time, before the angle of the sun changes. The Height's Ratio of the 2 objects will follow accordingly to the the Shadow's Ratio of the 2 objects. Based on the known principle that the Ratio of each corresponding sides in 2 similar triangles stays the same. It is recommended to make the necessary measurements outside, and then to use this app to overview the learning.



Resource Type
experiment  shadow  similar  similar-triangle  triangles 
Target Group (Age)
11 – 14
English (United States)
GeoGebra version
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