How Length Of Pyramid Was Measured?

 

In a dialogue given by Plutarch, the speaker addressing Thales says “placing your stick at the end of the shadow of the pyramid, you made by the sun’s rays two triangles, and so proved that the [height of the] pyramid was to the [length of the] stick as the shadow of the pyramid to the shadow of the stick.” The king Amasis, who was present, is said to have been amazed at this application of abstract science, and the Egyptians seem to have been previously unacquainted with the theorem.