3.4 Polyhedrons and Prisms Objective: to name polyhedrons and prisms

Warm Up Classify 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

Vocabulary Polyhedron – a three-dimensional figure in which each surface is shaped like a polygon Face – a flat surface that is shaped like a polygon Edge – the segment formed by the intersection of two faces Vertex – a point at which three or more edges intersect Prism – a polyhedron with two faces that have the same size and shape and lie in parallel planes Base – the two faces on a prism that are parallel to each other Cylinder – is not a prism because it has two circles as bases Pyramid – is not a prism because it does not have two bases Lateral 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.

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 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 edges: bases: ABCD, EFGH, ABFE, DCGH, ADHE, BCGF 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 edges: base: ABCDE Is this a prism?

Check It Out! Example 1a Classify the figure. Name the vertices, edges, and bases. cone vertex: N M edges: none base: •M Is this a prism?

Check It Out! Example 1b Classify the figure. Name the vertices, edges, and bases. triangular prism vertices: T, U, V, W, X, Y edges: bases: ∆TUV, ∆WXY 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