Pappus’s projective theorem

Directory

References

Images

Figure 7: Construction for Pappus' theorem (see text).

Pappus's projective theoremPappus of Alexandria (fl. ad 320) proved that the three points (x, y, z) formed by intersecting the six lines that connect two sets of three collinear points (A, B, C; and D, E, F) are also collinear.

Discover

African Americans demonstrating for voting rights in front of the White House as police and others watch, March 12, 1965. One sign reads, "We demand the right to vote everywhere." Voting Rights Act, civil rights.

Timeline of the American Civil Rights Movement

Statue of Nostradamus

Nostradamus and His Prophecies

Demystified - Do Lemmings Really Commit Mass Suicide? illustration

Do Lemmings Really Commit Mass Suicide?

Normandy Invasion: Omaha Beach. World War II. D-Day. Infographic. SPOTLIGHT VERSION

Facts and Figures About the Landings on Omaha Beach During the Normandy Invasion on June 6, 1944

Lake Mead (the impounded Colorado River) at the Hoover Dam. The light-coloured band of rock above the shoreline shows the decrease in water level in the first few years of the 21st century.

6 Lakes That Are Drying Up

San Francisco, California/USA-1/18/20: Womens March at Civic Center marching with signs of political protest regarding equality also embracing 2020 presidential candidates and celebrating equality

How Does the U.S. Government Define the Difference Between a Protest and a Riot?

Time zone map with standard time zones and International Date Line

Why Are Some Time Zones 30 Minutes Off Instead of an Hour?

Pappus’s projective theorem

geometry

Learn about this topic in these articles:

projective geometry

In projective geometry: Projective invariants
In its first variant, by Pappus of Alexandria (fl. ad 320) as shown in the figure, it only uses collinearity:
Read More