Words That Rhyme With "Pentahedron" :

2 syllables:

Kidron

3 syllables:

trihedron

4 syllables:

decahedron, hexahedron, octahedron, polyhedron, rhombohedron, tetrahedron

5 syllables:

dodecahedron, icosahedron, scalenohedron, trisoctahedron

7 syllables:

icositetrahedron