ratio/proportion/dilation | |

File Size: | 727 kb |

File Type: | wav |

## Ratio- proportional relation; rate

example: the ratio of 5 to 2, written 5:2 or 5/2

Proportion- comparative relation between things or magnitudes as to size, quantity, number, etc.

example: 2/3=6/9

Dilation- to make wider or larger; cause to expand

example:

## Scale- you can find the scale by taking the coordinates of one point and finding a common relationship to the cooresponding point.

## Practice Problem 1:the points of a trianlge are A(5,2), B(1,-4), and C(-1,0). they are dialated by 3.

Step 1-5(3), 2(3)= (15, 6)

Step 2-1(3), -4(3)=(3, -12)

Step 3- -1(3), 0(3)=(-3, 0)

Step 4- A' (15, 6) B' (3, -12) C' (-3, 0)

Step 2-1(3), -4(3)=(3, -12)

Step 3- -1(3), 0(3)=(-3, 0)

Step 4- A' (15, 6) B' (3, -12) C' (-3, 0)

## Practice Problem 2:

21=7x/10

Step 1-Multipy both sides by 10.

210=7x

Step 2-Divide each side by 7.

x=30

Step 1-Multipy both sides by 10.

210=7x

Step 2-Divide each side by 7.

x=30

## Practice Problem 3; Real World Problem: The perimeter of a pool is 408, and the ratio of its length to width is 10:7. Find the area of the pool.

Step 1-Write expressions for the length and width. The ratio 10:7 can be written as 10x and 7x.

Step 2-Write an equation to solve for x.

2l+2w=p

2(10x)+2(7x)=408

20x+14x=408

34x=408

x=12

Step 3-Length= 10x =10 (12) =120

Width=7x = 7 (12) = 84

Area= 10,080 ft.

Step 2-Write an equation to solve for x.

2l+2w=p

2(10x)+2(7x)=408

20x+14x=408

34x=408

x=12

Step 3-Length= 10x =10 (12) =120

Width=7x = 7 (12) = 84

Area= 10,080 ft.

## Practice Problem 4:

2/3=x/21

Step 1- Cross multiply 3x=2(21)

3x=42

Step 2- Divide by 3

x=14