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Polyhedra

Overview

Tetrahedron Octahedron Hexahedron Dodecahedron Icosahedron
Vertices 4 6 (2 × 3) 8 12 (4 × 3) 12
Edges 6 12 12 30 30
Faces 4 8 6 20 20 (8 + 4 × 3)
Face shape Equilateral triangle Equilateral triangle Square Regular pentagon Equilateral triangle
Schläfli symbol {3, 3} {3, 4} {4, 3} {5, 3} {3, 5}
Wythoff symbol 3 | 2 3 4 | 2 3 3 | 2 4 3 | 2 5 5 | 2 3
C&R symbol 33 34 43 53 35
Vertex configuration 3.3.3 3.3.3.3 4.4.4 5.5.5 3.3.3.3.3

Parameters

Entities

Parameter Symbol Name Description
p \(P\), \(V\) Vertex
e \(E\) Edge
f \(F\) Face
s \(S\) Solid

Properties

Parameter Symbol Name Description
r \(r\) Radius
t \(\theta\) Angle
h \(h\) Height
l \(l\) Length
a \(A\) Area
v \(V\) Volume

Combined

Parameter Symbol Name Description
p_c \(x\) Vertex coordinate
e_l \(a\) Edge length
f_a \(A0\) Face area
r_u \(R\), \(r_u\) Circumradius The circumradius of a cyclic polygon is a radius of the circle inside which the polygon can be inscribed. Similarly, the circumradius of a polyhedron is the radius of a circumsphere touching each of the polyhedron's vertices, if such a sphere exists.
r_i \(r\), \(r_i\) Inradius The radius of a polygon's incircle or of a polyhedron's insphere.
r_m \(\rho\), \(r_m\) Midradius The radius of the midsphere of a polyhedron, also called the interradius.
s_a \(A\) Surface area
s_v \(V\) Volume
s_t \(\omega\) Solid Angle
f_t_d \(a\) Dihedral Angle The dihedral angle is the angle between two planes.
s_t_s \(\beta\) Subtended Angle Subtended by an edge from the center for the Platonic solids.
p_t Vertex Angle

https://www.technologyuk.net/mathematics/geometry/platonic-solids.shtml