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Hello, I was wondering if I could get help on my unit test reveiw sheet. There are 4 problems, but the problems are still worth a great deal of my grade. If I could get help, with all or even a few, I will be thankful. The unit in geometry that I am focusing on is 'Similarity'.

 

Here they are:

 

1. It says Graph the Image of the figure after a dilation with the scale factor of 3/2 centered at (5,-5).

What would be the three coordinates of the dilation?

 

2. The length of angle CD is 9 units.

What is the length of the image of the line segment that after a dilation with a scale factor of 3/2? (Enter your answer in simplest form)

 

3. The larger triangle is the image of the smaller triangle after a dilation. The center of the dilation is (-2,-2). 

What is the scale factor used to create the dilation?

 

4. Point J is located at (2,5)  and point K is located at (4,19). What are the coordinates of the point that partitions the directed line segment JK in a 3:2 ratio?

 Dec 22, 2016
 #1
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( 1)  and (3)  can't be answered without a figure  shown.....!!!!

 

 

(2)    9 * (3/2)  =  27/2   =   13.5 units long after  dilation

 

 

4. Point J is located at (2,5)  and point K is located at (4,19). What are the coordinates of the point that partitions the directed line segment JK in a 3:2 ratio?

 

The line is divided into 5 parts........the partition point will be located at  3/5 of the way between (2,5) and ( 4, 19)  =   [ 2 + (4 − 2)(3/5) ,  5 + (19 − 5) (3/5)  ]   =  [ 2 + 6/5 , 5 + 42/5]   =  [ 16/5 , 67/5]

 

Proof.....distance beween  ( 2,5)  and (4, 19)  = √[ (4 − 2)^2 + ( 19  − 5)^2 ]  =  √ [ 4 + 196]  = √200 = 10√2

 

Distance beween  ( 2,5)  and (16/5, 67,5)  = √[ (16/5 − 2)^2 + ( 67/5  − 5)^2 ]  =

√[ (6/5)^2 + ( 42/5 )^2 ]   =  √ [ 36  + 1764] / 5  =  √1800 / 5   = 30√2 / 5 =  6√2

 

And    6√2  /10 √2  =   6 / 10   =  3/5

 

 

 

cool cool cool

 Dec 22, 2016
 #2
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Thanks so much for your help! I appreciate it lots. :) How can I post a picture of problems (1) and (3)?

 Dec 22, 2016

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