Euclid:

Of trilateral figures, an equilateral triangle is that which has its three sides equal, an isosceles triangle that which has two of its sides alone equal, and a scalene triangle that which has its three sides unequal.

— Euclid Ancient

Father of geometry

Context

Definition in 'Elements'

Date / Period

300 BC

Source

https://mathcs.clarku.edu/~djoyce/java/elements/bookI/defI20.html

Verification

Unverifiable

Explanation

Found in 1 providers: deepseek

Method

Cross Reference

Sources Checked

1 source

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