arc

Directory

References

Discover

Thumbnail for flags that look alike quiz Russia, Slovenia, Iceland, Norway

Flags That Look Alike

Los Angeles Police Department wanted flyer on Elizabeth Short, aka the "Black Dahlia," who was brutally murdered in January 1947. The FBI supported the Los Angeles Police Department in the case, including by identifying Short through her fingerprints that

America’s 5 Most Notorious Cold Cases (Including One You May Have Thought Was Already Solved)

Diverse elementary school children wearing school uniforms running outside of school. Boys girls

Pro and Con: School Uniforms

Woman tied to a ducking stool, a method of punishment by means of humiliation, beating, or death. (cucking stool)

8 Unusual Punishments Inflicted on Women Throughout History

Title: Senate Square, St. Petersburg, December 14, 1825: repression of the troop mutiny - watercolor by Carl Ivanovitch Kollman, 1825 depicts Decembrist uprising clashing with cavalry, with spectators watching. (new style December 26, 1825) Europe. Saint

8 of the Largest Empires in History

Close up of books. Stack of books, pile of books, literature, reading. Homepage 2010, arts and entertainment, history and society

12 Novels Considered the “Greatest Book Ever Written”

A Factory Interior, watercolor, pen and gray ink, graphite, and white goache on wove paper by unknown artist, c. 1871-91; in the Yale Center for British Art. Industrial Revolution England

Inventors and Inventions of the Industrial Revolution

arc

mathematics

Learn about this topic in these articles:

significance in measurement of Earth’s size

In geoid: The ancients
Knowing the length of an arc (l) and the size of the corresponding central angle (a) that it subtends, one can obtain the radius of the sphere from the simple proportion that length of arc to size of the great circle (or circumference, 2πR, in which R is Earth’s radius)…
Read More