Page 108 - Math Course 1 (Book 2)

Three-Dimensional Figures

Mo. 10

Lesson 1 polyhedron

A polyhedron is a solid with f at surfaces that are
polygons.

KEY CONCEPTS:
1. Identify three-dimensional f gures.
2. Draw various views of three-dimensional
f gures.

tetrahedron cube
octahedron

MO. 10 - L1a

Identifying Three-Dimensional
Figures

Vocabulary A-Z dodecahedron icosahedron

Let us learn some vocabulary

plane
A plane is a two dimensional f at surface that
extends in all directions.

VERTEX
EDGE

FACE

solids edge
Intersecting planes can also form three-dimensional An edge is where two planes intersect in a line.
f gures or solids.

vertex
A vertex is where three or more planes intersect in a
point.

face
A face is a f at surface.

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