Birotunda
In geometry, a birotunda is any member of a family of dihedral-symmetric polyhedra, formed from two rotunda adjoined through the largest face. They are similar to a bicupola but instead of alternating squares and triangles, it alternates pentagons and triangles around an axis. There are two forms, ortho- and gyro-: an orthobirotunda has one of the two rotundas is placed as the mirror reflection of the other, while in a gyrobirotunda one rotunda is twisted relative to the other.
The pentagonal birotundas can be formed with regular faces, one a Johnson solid, the other a semiregular polyhedron:
Other forms can be generated with dihedral symmetry and distorted equilateral pentagons.
See also
References
Podcasts:
-
by Marty Robbins
-
by Don Williams
-
by Ray Price
-
by Nat King Cole
-
by King's X
-
by Marvin Gaye
-
by Dianne Reeves
-
by Shelby Lynne
-
by Quietdrive
-
by Roch Voisine
-
by Vanessa Paradis
-
by Mavericks
-
by The Mavericks
-
by Mark Erelli
-
by Dany Brillant
-
by Parlotones
-
by Secondhand Serenade
-
by Aeon
-
by Number One Gun
-
by Lights
-
by Saturnus
-
by Sick Shift
-
by Richard Lloyd
-
by SocialBurn
-
by Clique Girlz
-
by Jamie O'Hara
-
by Warriors Of Destruction
-
by Monika
-
by Angela Ammons
-
by Alvin Stardust
-
by ANGELA AMMONS l
-
by Underwater Circus
-
by Bien Desocupados
-
by Vainglory
-
by Cheri Dennis
-
by Bandslam
-
by All The Right Moves
-
by Carl Mann
-
by Cravin' Melon
-
by Scott Porter & The Glory Dogs
-
by Brand New Hearts
-
by X-phaze
-
by Nate James
-
by Jacob Golden
-
by Freddie Hart
Pretend
by: Marty RobbinsPretend you're happy when you're blue
It isn't very hard to do
And you'll find happiness without an end
Whenever you pretend
Remember anyone can dream
It's never bad as it may seem
The little things you haven't got can be a lot
If you would pretend
You'll find a love you can share
One you can call all your own
Just close your eyes, she'll be there
You'll never be alone
And when you sing this melody
You'll be pretending just like me
The world is mine, it can be yours, my friend
If only you pretend
Just close your eyes, she'll be there
You'll never be alone
And if you sing this melody
You'll be pretending just like me
The world is mine, it can be yours, my friend
So why don't you pretend