Euclidean geometry

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Three theorems of congruent triangles

Proof that the sum of the angles in a triangle is 180 degrees

Fundamental theorem of similarity

Area of a triangle

Pythagorean theorem

Chord in a circle

Three-dimensional shapes

Platonic solids

Figure 2: Illustration of Euclid's fifth postulate (see text).

quadrilateral of Omar Khayyam

For Students

Euclidean geometry summary

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Euclidean geometry: Related Content

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Photos

Three theorems of congruent triangles

Proof that the sum of the angles in a triangle is 180 degrees

Fundamental theorem of similarity

Area of a triangle

Pythagorean theorem

Chord in a circle

Three-dimensional shapes

Figure 2: Illustration of Euclid's fifth postulate (see text).

quadrilateral of Omar Khayyam

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Topics

Pythagorean theorem triangle inequality method of exhaustion quadrature parallel postulate fundamental theorem of similarity method of indivisibles Cavalieri’s principle Thales’ rectangle side-angle-side theorem topology analytic geometry differential geometry projective geometry non-Euclidean geometry algebraic geometry catastrophe theory Pappus’s theorem Ceva’s theorem length, area, and volume

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geometry: Euclidean geometry

Key People

Euclid

Euclid

Greek mathematician

David Hilbert

David Hilbert

German mathematician

Maryam Mirzakhani

Maryam Mirzakhani

Iranian mathematician

Adrien-Marie Legendre

French mathematician

Quiz

Italian-born physicist Dr. Enrico Fermi draws a diagram at a blackboard with mathematical equations. circa 1950.

Define It: Math Terms

Equations written on blackboard

Numbers and Mathematics

Equations written on blackboard

All About Math Quiz