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Mathematics

Similar Triangles and Their Applications

Quick fact

The Greek philosopher Thales measured the height of the Great Pyramid of Giza by comparing its shadow with the shadow of a stick, using the property of similar triangles over 2,500 years ago.

Why this is interesting

You can measure the height of a tree without climbing it—just by measuring a shadow and using a stick. How is that possible? The answer lies in a simple yet powerful idea: similar triangles.