- 49 Views
- Uploaded on

Download Presentation
## PowerPoint Slideshow about ' 5-Minute Check 1' - samuel-pitts

**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

There are 480 sophomores and 520 juniors in a high school. Find the ratio of juniors to sophomores.

A strip of wood molding that is 33 inches long is cut into two pieces whose lengths are in the ratio of 7:4. What are the lengths of the two pieces?

520

480

13

12

=

7x + 4x = 33, x = 3; 7(3) = 21 & 4(3) = 12

x = 7

x = 2

x = 3.25

5-Minute Check 1Learning Target:

I will be able to identify similar polygons and solve problems using the properties of similar polygons.

Standard 4.0

Students prove basic theorems involving similarity.

Ch 9.2Similar Polygons- polygon – a closed figure in a plane formed by segments called sides.
- similar polygons – polygons that are the same shape but not necessarily the same size.
- scale drawing – used to represent something that is too large or too small to be drawn to actual size.

Identify Similar Polygons

Step 1 Compare corresponding angles.

Since all angles of a rectangle are right angles and right angles are congruent, corresponding angles are congruent.

Step 2 Compare corresponding sides.

Answer:Since corresponding sides are not proportional, ABCD is not similar to FGHK. So, the menus are not similar.

Example 24

__

5

Identify Similar Polygons

Step 1 Compare corresponding angles.

Since all angles of a rectangle are right angles and right angles are congruent, corresponding angles are congruent.

Step 2 Compare corresponding sides.

Answer:Since corresponding sides are proportional, ABCD ~ RSTU. So, the menus are similar with a scale factor of .

Example 2A.BCDE ~ FGHI, scale factor =

B.BCDE ~ FGHI, scale factor =

C.BCDE ~ FGHI, scale factor =

D.BCDE is not similar to FGHI.

1

4

3

__

__

__

2

5

8

Original: New:

A. Thalia is a wedding planner who is making invitations. Determine whether the size for the new invitations is similar to the original invitations used. If so, choose the correct similarity statement and scale factor.

Example 2A.BCDE ~ WXYZ, scale factor =

B.BCDE ~ WXYZ, scale factor =

C.BCDE ~ WXYZ, scale factor =

D.BCDE is not similar to WXYZ.

1

4

3

__

__

__

2

5

8

Original: New:

B. Thalia is a wedding planner who is making invitations. Determine whether the size for the new invitations is similar to the original invitations used. If so, choose the correct similarity statement and scale factor.

Example 2The scale factor ABCDE to RSTUV is or .

Write a proportion to find the length of DC.

4

__

AE

___

7

VU

Since DC AB and AE DE, the perimeter of ABCDE is 6 + 6 + 6 + 4 + 4 or 26.

Use a Scale Factor to Find Perimeter

Write a proportion.

4(10.5) = 7 ● DC Cross Products Property

6 = DC Divide each side by 7.

Example 4Use a Scale Factor to Find Perimeter

Use the perimeter of ABCDE and scale factor to write a proportion. Let x represent the perimeter of RSTUV.

Theorem 7.1

Substitution

4x = (26)(7) Cross Products Property

x = 45.5 Solve.

Answer:The perimeter of ABCDE is 26 and the perimeter of RSTUV is 45.5.

Example 4
Download Presentation

Connecting to Server..