# Geometry/Neutral Geometry/Euclid's First Four Postulates

< Geometry | Neutral Geometry

## Euclid's Postulate I[edit | edit source]

For every point P and for every point Q not equal to P there exists a unique line that passes through P and Q

### Explanation[edit | edit source]

Informally, this postulate says that two points determine a unique line.

## Euclid's Postulate II[edit | edit source]

For every segment AB and for every segment CD there exists a unique point E on line AB (needs LaTex formatting) such that B is between A and E and segment CD is congruent to segment BE

### Explanation[edit | edit source]

[To Come]

## Euclid's Postulate III[edit | edit source]

For every point O and every point A not equal to O, there exists a circle with center O and radius OA

### Explanation[edit | edit source]

[To Come]

## Euclid's Postulate IV[edit | edit source]

All right angles are congruent to one another

### Explanation[edit | edit source]

[To Come]