Spherical trigonometry | Types of polygons

Pentagramma mirificum

Pentagramma mirificum (Latin for miraculous pentagram) is a star polygon on a sphere, composed of five great circle arcs, all of whose internal angles are right angles. This shape was described by John Napier in his 1614 book Mirifici Logarithmorum Canonis Descriptio (Description of the Admirable Table of Logarithms) along with rules that link the values of trigonometric functions of five parts of a right spherical triangle (two angles and three sides). The properties of pentagramma mirificum were studied, among others, by Carl Friedrich Gauss. (Wikipedia).

Pentagramma mirificum
Video thumbnail

✽HOW TO DRAW -MANDALA ART✽

#Mandala MANDALA LOVERS ALERT- Mandala (Sanskrit: मण्डल, lit, circle) is a spiritual and ritual symbol in Indian religions, representing the universe-check out more videos about mandala below-. * check out my Blog Post for details on Mandala supplies- https://www.theartgeekblog.com/post/mu

From playlist Bag

Video thumbnail

Syphilis: Treponema pallidum

Syphilis is another infection that is typically caused by sexual contact, thanks to the pathogen Treponema pallidum. What does this bacterium do? How is the infection treated? Let's take a closer look now. Script by Kellie Vinal Watch the whole Microbiology playlist: http://bit.ly/ProfDa

From playlist Microbiology/Infectious Diseases

Video thumbnail

What's a Pentagram? Geometry Terms and Definitions

Learn the mathematical name for this famous shape. Geometer: Louise McCartney Artwork: Kelly Vivanco Director: Michael Harrison Written & Produced by Kimberly Hatch Harrison and Michael Harrison ♦♦♦♦♦♦♦♦♦♦ Ways to support our channel: ► Join our Patreon : https://www.patreon.com/socr

From playlist Socratica: The Geometry Glossary Series

Video thumbnail

Poliomyelitis (Poliovirus)

Poliomyelitis is a disease caused by the poliovirus, which has the ability to infect motor neurons in the spinal cord and cause paralysis. American President Franklin Roosevelt was famously crippled by polio. The poliovirus exists in a few different serotypes, which belong to the genus ent

From playlist Microbiology/Infectious Diseases

Video thumbnail

LANTHANIDES - a quick definition

A quick definition of the lanthanides. Chem Fairy: Louise McCartney Director: Michael Harrison Written and Produced by Kimberly Hatch Harrison ♦♦♦♦♦♦♦♦♦♦ Ways to support our channel: ► Join our Patreon : https://www.patreon.com/socratica ► Make a one-time PayPal donation: https://ww

From playlist Chemistry glossary

Video thumbnail

Whooping Cough: Bordetella pertussis

Whooping cough, caused by Bordetella pertussis, is a baby killer. It goes all the way back to the middle ages, so let's get a closer look at this bacterium now. Script by Kellie Vinal Watch the whole Microbiology playlist: http://bit.ly/ProfDaveMicrobio General Chemistry Tutorials: http

From playlist Microbiology/Infectious Diseases

Video thumbnail

Measles (Genus Morbillivirus)

If you're above a certain age, you've heard of the measles. This is a particularly nasty viral infection that used to be incredibly common, though is now largely eradicated thanks to vaccinations. Although, anti-vaccine sentiment has caused a slight resurgence in cases. What is this virus

From playlist Microbiology/Infectious Diseases

Video thumbnail

Angiosperms: Flowering Plants

We just learned about gymnosperms, and the incredible evolutionary advantages they had over their ancestors. But the next leap forward for plants was even more impressive. Angiosperms are flowering plants, so any plant with flowers or fruits is an angiosperm. And instead of fertilizing by

From playlist Botany

Video thumbnail

Multidrug-Resistant Tuberculosis (MDR-TB): Mycobacterium tuberculosis

What is tuberculosis? Just like the rest of these diseases, it's caused by a bacterium, specifically Mycobacterium tuberculosis. This one is tricky because there are strains that are becoming increasingly resistant to antibiotics, so let's learn what we can about these fellas, so that we c

From playlist Microbiology/Infectious Diseases

Video thumbnail

These Microbes Hunt and Paralyze Their Prey

To learn more about the eating habits of microorganisms, check out the full video here: https://youtu.be/io731XY8fH8 Shop The Microcosmos: https://www.microcosmos.store Follow Journey to the Microcosmos: Twitter: https://twitter.com/journeytomicro Facebook: https://www.facebook.com/Journ

From playlist Microcosmos Shorts

Related pages

Star polygon | Great circle | Arthur Cayley | Rotation | Carl Friedrich Gauss | Five points determine a conic | Trigonometric functions | Cartesian coordinate system | Right triangle | Ellipse | Gnomonic projection | Spherical trigonometry | Conic section | Sphere | Right angle | Internal and external angles | Mirifici Logarithmorum Canonis Descriptio