19 terms

# Chapter 12 Geometry Test

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polyhedron
a solid that is bounded by polygons, called faces, that enclose a single region of space
edge
an edge of a polyhedron is a line segment formed by the intersection of two faces
vertex
a vertex of a polyhedron is a point where three or more edges meet
regular
if a polyhedron is regular if all of its faces are congruent regular polygons
convex
a polyhedron is convex if any two points on its surface can be connected by a segment that lies entirely inside or on the polyhedron
cross section
the of intersection of a plane and a solid
platonic solids
-tetrahedron (4 faces)
-octahedron (8 faces)
-dodecahedron (12 faces)
-icosahedron (20 faces)
Euler's Theorem
F + V = E + 2
surface area
SA= LA + 2B
Volume Congruence Postulate
if two polyhedra are congruent, then they have the same volume
the volume of a solid is the sum of the volumes of all its non-overlapping parts
Cavalieri's Principle
if two solids have the same height and the same cross-sectional area at every level, then they have the same volume
volume of a prism or cylinder
V=Bh
volume of a pyramid or cone
V=(1/3)Bh
sphere
the locus of points in space that are a given distance from a point (center of the sphere)