38 terms

# Avaondale Geo 3D

###### PLAY
polyhedron
a solid figure with many sides, such as a pyramid
face
a surface forming part of the outside of an object
edge
a sharp side formed by the intersection of two surfaces of an object
vertex
the point of intersection of lines or the point opposite the base of a figure
regular polyhedron
any one of five solids whose faces are congruent regular polygons and whose polyhedral angles are all congruent
convex
curving or bulging outward
cross section
a section created by a plane cutting a solid perpendicular to its longest axis
platonic solids
tetrahedron, cube, regular octahedron, regular dodecahedron, regular icosahedron
tetrahedron
any polyhedron having four plane faces
octahedron
any polyhedron having eight plane faces
dodecahedron
any polyhedron having twelve plane faces
icosahedron
any polyhedron having twenty plane faces
prism
a polyhedron with two congruent and parallel faces (the bases) and whose lateral faces are parallelograms
bases
polygons that make up the bottoms of a polyhedron
lateral faces
the faces that are not the base of a parallelogram
right prism
each lateral edge is perpendicular to both bases
oblique prism
a prism that is not a right prism
surface area of a polyhedron
the sum of the areas of the faces of the polyhedron
lateral area of a polyhedron
the sum of the areas of the lateral faces of a polyhedron.
net
a two-dimensional pattern that you can fold to form a three-dimensional figure
cylinder
a solid bounded by a cylindrical surface and two parallel planes (the bases)
right cylinder
A cylinder with the axis perpendicular to both bases.
lateral area of a cylinder
la=2πrh
surface area of a cylinder
SA=2πr²+2πrh
pyramid
a polyhedron having a polygonal base and triangular sides with a common vertex
regular pyramid
a pyramid whose base is a regular polygon and whose lateral faces are congruent isosceles triangles
circular cone
base is a circle & it has 1 vertex.
lateral surface of a cone
LSA = ½PL
(P is the perimeter/circumference of the base, L is the slant height)
right cone
A cone in which a perpendicular line drawn from the base to the tip (vertex) passes through the center of the base
volume of a solid
V=lwh
sphere
a three-dimensional closed surface such that every point on the surface is equidistant from the center
center of a sphere
The point inside a sphere that is the same distance from every point on the sphere.