3.4 polyhedrons and prisms objective: to name polyhedrons and prisms
TRANSCRIPT
3.4 Polyhedrons and Prisms
Objective: to name polyhedrons and prisms
Warm UpClassify each polygon.
1. a polygon with three congruent sides
2. a polygon with six congruent sides and six congruent angles
3. a polygon with four sides and with opposite sides parallel and congruent
equilateral triangle
regular hexagon
parallelogram
Polyhedron – a three-dimensional figure in which each surface is shaped like a polygon
Face – a flat surface that is shaped like a polygonEdge – the segment formed by the intersection of two facesVertex – a point at which three or more edges intersectPrism – a polyhedron with two faces that have the same size and
shape and lie in parallel planesBase – the two faces on a prism that are parallel to each otherCylinder – is not a prism because it has two circles as basesPyramid – is not a prism because it does not have two basesLateral face – the faces that are not the bases, they are shaped like
a parallelogram.Right – all lateral faces are rectangles that lie in planes perpendicular to the bases.Oblique – figures that are not right, they are slanted like they are
getting pushed over.
Vocabulary
Three-dimensional figures, or solids, can be made up of flat or curved surfaces. Each flat surface is called a face. An edge is the segment that is the intersection of two faces. A vertex is the point that is the intersection of three or more faces.
A cube is a prism with six square faces. Other prisms and pyramids are named for the shape of their bases.
Example 1A: Classifying Three-Dimensional Figures
Classify the figure. Name the vertices, edges, and bases.
cube
vertices: A, B, C, D, E, F, G, H
bases: ABCD, EFGH, ABFE, DCGH, ADHE, BCGF
edges:
Is this a prism?
Example 1B: Classifying Three-Dimensional Figures
Classify the figure. Name the vertices, edges, and bases.
pentagonal pyramid
vertices: A, B, C, D, E, F
base: ABCDE
edges:
Is this a prism?
Check It Out! Example 1a
Classify the figure. Name the vertices, edges, and bases.
vertex: N
cone
edges: none
base: •M
M
Is this a prism?
Check It Out! Example 1b
Classify the figure. Name the vertices, edges, and bases.
triangular prism
bases: ∆TUV, ∆WXY
vertices: T, U, V, W, X, Y
edges:
Is this a prism?
Check It Out! Example 3a
Is this a prism? If it is name it.
Hexagonal prism
Example 4A: Food Application
Is this piece of cheese a prism? If it is, name it.
Triangular Prism
Check It Out! Example 4
Is this watermelon a prism? If so, name it.
Cube or rectangular prism
Lesson Quiz:
1. Classify the figure. Name the vertices, edges, and bases.
triangular prism; vertices: A, B, C, D, E, F;
bases: ∆ABC and ∆DEF
edges:
Homework
section 3-4 # 1-19