- 欧几里得几何 ōujǐlǐdéjǐhé Euclidean geometrythe mathematical study of flat space and shapes based on the axioms of the ancient Greek mathematician Euclid
- 欧几里得几何学 ōujǐlǐdéjǐhéxué Euclidean geometrythe branch of mathematics and mathematical system attributed to the ancient Greek mathematician Euclid
- 欧几里得算法 ōujǐlǐdésuànfǎ Euclidean algorithman efficient method for computing the greatest common divisor of two integers by repeatedly replacing the larger number with the remainder of its division by the smaller number