- 192 Views
- Uploaded on

Download Presentation
## PowerPoint Slideshow about 'Lesson 9' - tejana

**An Image/Link below is provided (as is) to download presentation**

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -

Presentation Transcript

### Lesson 9

Three-Dimensional Geometry

Planes

- A plane is a flat surface (think tabletop) that extends forever in all directions.
- It is a two-dimensional figure.
- Three non-collinear points determine a plane.
- So far, all of the geometry we’ve done in these lessons took place in a plane.
- But objects in the real world are three-dimensional, so we will have to leave the plane and talk about objects like spheres, boxes, cones, and cylinders.

Volume and Surface Area

- The volume of a three-dimensional object measures the amount of “space” the object takes up.
- Volume can be thought of as a capacity and units for volume include cubic centimeters cubic yards, and gallons.
- The surface area of a three-dimensional object is, as the name suggests, the area of its surface.

H

W

L

Volume and Surface Area of a Box- The volume of a box is found by multiplying its three dimensions together:
- The surface area of a box is found by adding the areas of its six rectangular faces. Since we already know how to find the area of a rectangle, no formula is necessary.

Cubes

- A cube is a box with three equal dimensions (length = width = height).
- Since a cube is a box, the same formulas for volume and surface area hold.
- If s denotes the length of an edge of a cube, then its volume is and its surface area is

Prisms

- A prism is a three-dimensional solid with two congruent bases that lie in parallel planes, one directly above the other, and with edges connecting the corresponding vertices of the bases.
- The bases can be any shape and the name of the prism is based on the name of the bases.
- For example, the prism shown at right is a triangular prism.
- The volume of a prism is found by multiplying the area of its base by its height.
- The surface area of a prism is found by adding the areas of all of its polygonal faces including its bases.

Pyramids

- A pyramid is a three-dimensional solid with one polygonal base and with line segments connecting the vertices of the base to a single point somewhere above the base.
- There are different kinds of pyramids depending on what shape the base is. To the right is a rectangular pyramid.
- To find the volume of a pyramid, multiply one-third the area of its base by its height.
- To find the surface area of a pyramid, add the areas of all of its faces.

Download Presentation

Connecting to Server..