9-1a surface area of prisms

9-1A Surface Area of Prisms

What is a prism?

What are the bases of a prism?

What are the lateral faces of a prism?

What is a right prism?

What is an oblique prism?

What is lateral area?

What is surface area?

True or False?1. Rectangular prisms are often referred to

as boxes.

2. Each prism has two lateral faces.

3. The length of an altitude is the height of a prism.

4. If the lateral edges of a prism are perpendicular to its bases, the prism is an oblique prism.

5. The lateral area of a prism is the total area of all of its faces including the bases.

Open your book to page 604

Read pages 604 to 606

Create a chart with the highlighted vocabulary words and a picture showing the vocabulary word or words.

Hint—start by drawing one prism showing the first four highlighted words. Continue from there.

True or False?1. Rectangular prisms are often referred to

as boxes.

2. Each prism has two lateral faces.

3. The length of an altitude is the height of a prism.

4. If the lateral edges of a prism are perpendicular to its bases, the prism is an oblique prism.

5. The lateral area of a prism is the total area of all of its faces including the bases.

Definition

The light through the prism on the window made a rainbow on the wall.

A prism is a polyhedron with two identical polygonal faces called bases that lie in parallel planes.

The other parallelogram-shaped faces are lateral faces.

Rectangular Prism

We often refer to rectangular prisms as boxes.

Altitude or Height?

An altitude of a prism is a segment perpendicular to both bases whose endpoints are in the planes of the bases.

The length of an altitude is the height of the prism.

AltitudeSee page 604 for other altitudes.

Right or Oblique?

Right prism—the lateral edges of the prism are perpendicular to its bases.

Oblique prism---the lateral edges of the prism are not perpendicular to its bases.

Classify each prism.

Lateral AreaLateral area is the sum of the areas of the

lateral faces of a prism.

Theorem

The lateral area of a right prism is the product of the perimeter of its base and the height of the prism.

LA = ph

Lateral Area

b

Sides only

No bases

Surface Area

The surface area of the prism is the total area of all of its faces including the bases.

TheoremThe surface area of a right prism is the sum

of its lateral area and the areas of its bases.

SA = LA (ph) + 2B

Surface Area

SA = P h + 2 (1/2 b h)

or

Lateral Area and Surface Area

Look at the top of your formula chart.

The first question you need to ask is:

What shape is the base?

Find the shape at the top. Then ask, what kind of figure is it and go to that formula.

There is a key for all of the abbreviations at the bottom of the page.

Find the lateral area of the right prism with right triangular bases.

Ask: What is the shape of the base?

Triangle

Find the triangle LA formula

hsss LA

91086LA 21624(9)LA

68

10

9

Find the surface area of the right prism with right triangular bases.

Ask: What is the shape of the base?

Triangle

Find the triangle SA formula

6)2(1/2)(8)(10)(9)8(6SA

68

10

9

26448216SA

True or False?

1. Rectangular prisms are often referred to as boxes.

2. Each prism has two lateral faces.

3. The length of an altitude is the height of a prism.

4. If the lateral edges of a prism are perpendicular to its bases, the prism is an oblique prism.

5. The lateral area of a prism is the total area of all of its faces including the bases.

Assignment 9-1A

Page 606, 1-16,

skip 12

NO FORMULAS WITH NUMBERSNO CREDIT