10-6 three-dimensional figures warm up warm up lesson presentation lesson presentation problem of...
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10-6 Three-Dimensional Figures
2. The radius of a circle is 9 cm. What is its circumference?
1. The diameter of a circle is 12 in. What is the circumference?
Warm UpSolve. Use 3.14 for .
37.68 in.
56.52 cm
452.16 ft2
3. Find the area of a circle with a 12 ftradius.
10-6 Three-Dimensional Figures
Problem of the Day
To measure the perimeter of her square patio, Becky used an old bicycle wheel with a 22 in. diameter. She rolled the wheel from one corner of the patio along the edge to the next. The wheel made 6.75 revolutions. What is the perimeter in feet of the patio? Use 3.14 for . 155.43 ft
10-6 Three-Dimensional Figures
Vocabulary
polyhedron cylinderface pyramidedge conevertex sphereprismbase
10-6 Three-Dimensional Figures
A polyhedron is a three-dimensional object with flat surfaces, called faces, that are polygons.
When two faces of a three-dimensional figure share a side, they form an edge. A point at which three or more edges meet is a vertex (plural: vertices).
10-6
10-6 Three-Dimensional Figures
Additional Example 1: Identifying Faces, Edges, and Vertices
Identify the number of faces, edges, and vertices on each three-dimensional figure.
A.
B.
5 faces
8 edges
5 vertices
7 faces
15 edges
10 vertices
10-6 Three-Dimensional Figures
Check It Out: Example 1
Identify the number of faces, edges, and vertices on each three-dimensional figure.
A.
B.
6 faces
12 edges
8 vertices
5 faces
9 edges
6 vertices
10-6 Three-Dimensional Figures
A prism is a polyhedron with two congruent, parallel bases, and other faces that are all parallelograms. A prism is named for the shape of its bases. A cylinder also has two congruent, parallel bases, but bases of a cylinder are circular. A cylinder is not a polyhedron because not every surface is a polygon.
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10-6 Three-Dimensional Figures
A pyramid has one polygon-shaped base and three or more triangular faces that share a vertex. A pyramid is named for the shape of its base. A cone has a circular base and a curved surface that comes to a point. A sphere has no base and one curved surface. All points on the surface are the same distance from a point called the center of the sphere.
10-6 Three-Dimensional Figures
Cones and spheres are not polyhedrons because they have curved surfaces.
Helpful Hint
10-6 Three-Dimensional Figures
Additional Example 2A: Naming Three-Dimensional Figures
Name the three-dimensional figure represented by the object.
The figure is not a polyhedron.
There is a curved surface.
The figure represents a cylinder.
There are two congruent, parallel bases.
The bases are circles.
10-6 Three-Dimensional Figures
Additional Example 2B: Naming Three-Dimensional Figures
Name the three-dimensional figure represented by the object.
The figure is a polyhedron.
All the faces are flat and are polygons.
The figure is a triangular pyramid.
There is one base and the other faces are triangles that meet at a point, so the figure is a pyramid. The base is a triangle.
10-6 Three-Dimensional Figures
Additional Example 2C: Naming Three-Dimensional Figures
Name the three-dimensional figure represented by the object.
The figure is a polyhedron.
All the faces are flat and are polygons.
The figure is a rectangular prism.
There are two congruent, parallel bases, so the figure is a prism. The bases are rectangles.
10-6 Three-Dimensional Figures
Check It Out: Example 2A
Name the three-dimensional figure represented by the object.
The figure is a polyhedron.
All the faces are flat and are polygons.
The figure is a square pyramid.
There is one base and the other faces are triangles that meet at a point, so the figure is a pyramid. The base is a square.
10-6 Three-Dimensional Figures
Check It Out: Example 2B
Name the three-dimensional figure represented by the object.
The figure is a polyhedron.
All the faces are flat and are polygons.
The figure is a rectangular prism.
There are two congruent, parallel bases, so the figure is a prism. The bases are rectangles.
10-6 Three-Dimensional Figures
Check It Out: Example 2C
Name the three-dimensional figure represented by the object.
The figure is not a polyhedron.
There is a curved surface.
The figure represents a cylinder.
There are two congruent, parallel bases.
The bases are circles.
10-6 Three-Dimensional Figures
Standard Lesson Quiz
Lesson Quizzes
Lesson Quiz for Student Response Systems
10-6 Three-Dimensional Figures
Lesson Quiz
1. Identify the number of faces, edges, and vertices in the figure shown.
Identify the figure described.
2. two congruent circular faces connected by a
curved surface
3. one flat circular face and a curved lateral
surface that comes to a point
cylinder
8 faces, 18 edges, and 12 vertices
cone
10-6 Three-Dimensional Figures
1. Identify the number of faces, edges, and vertices in the figure shown.
A. 9 faces, 21 edges, and 14 vertices B. 21 faces, 9 edges, and 14 verticesC. 9 faces, 14 edges, and 21 verticesD. 21 faces, 14 edges, and 9 vertices
Lesson Quiz for Student Response Systems
10-6 Three-Dimensional Figures
2. Identify the figure described. A square base with four triangles that come to a point.
A. square prism B. square pyramid C. rectangular prismD. rectangular pyramid
Lesson Quiz for Student Response Systems