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Triangle UVW is the preimage of triangle RST with a scale factor of 3. Find the area of triangle UVW if the area of triangle RST is 9 cm2.
81 cm2
27 cm2
18 cm2
9 cm2
 11 months ago
 11 months ago
Triangle UVW is the preimage of triangle RST with a scale factor of 3. Find the area of triangle UVW if the area of triangle RST is 9 cm2. 81 cm2 27 cm2 18 cm2 9 cm2
 11 months ago
 11 months ago

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srossdBest ResponseYou've already chosen the best response.1
An intuitive way to think about this is that area is the square of distance. So, when you scale the distances of the sides by 3, the area scales by 9. So, 9 cm2 becomes 81 cm2.
 11 months ago

Joshuam1Best ResponseYou've already chosen the best response.0
wow that was simple O_O
 11 months ago

Joshuam1Best ResponseYou've already chosen the best response.0
I have some similar questions. Think you can have a look?
 11 months ago

Joshuam1Best ResponseYou've already chosen the best response.0
Quadrilateral HIJK is the preimage of quadrilateral LMNO. Find the scale factor, t.
 11 months ago

Joshuam1Best ResponseYou've already chosen the best response.0
the options are 9/4 , 5/3, 9/25, 3/2
 11 months ago

srossdBest ResponseYou've already chosen the best response.1
So, 375/135 = 2.77ish. You know from the last question that that's the square of the scale factor. Square root it and you get 1.66ish. So, 5/3.
 11 months ago

Joshuam1Best ResponseYou've already chosen the best response.0
okay i have another I'm just working out what you said so i can have it for myself
 11 months ago

srossdBest ResponseYou've already chosen the best response.1
Okay, let me know if you have any questions.
 11 months ago

Joshuam1Best ResponseYou've already chosen the best response.0
Find WZ if the area of trapezoid ABCD is 225 cm2, the area of trapezoid WXYZ is 81 cm2, and AD is 35 cm.
 11 months ago

Joshuam1Best ResponseYou've already chosen the best response.0
21 cm 12.6 cm 58.3 cm 97.2 cm
 11 months ago

srossdBest ResponseYou've already chosen the best response.1
So, find the scale factor first, like I did in the last question.
 11 months ago

srossdBest ResponseYou've already chosen the best response.1
Not quite, you forgot to take the square root.
 11 months ago

Joshuam1Best ResponseYou've already chosen the best response.0
find the sqrt of 2.77?
 11 months ago

srossdBest ResponseYou've already chosen the best response.1
Right, 225/81=2.77, but that's the ratio of the areas. To turn that into the ratio of lengths, you need the square root.
 11 months ago

srossdBest ResponseYou've already chosen the best response.1
Right, so now use that to find WZ.
 11 months ago

srossdBest ResponseYou've already chosen the best response.1
Right, so WZ = 21. Good job!
 11 months ago

Joshuam1Best ResponseYou've already chosen the best response.0
:D sweet 2 more questions
 11 months ago

Joshuam1Best ResponseYou've already chosen the best response.0
Find the area of the preimage rectangle QRST if the area of the image rectangle DEFG is 54 cm^2 and the scale factor is 3/2
 11 months ago

Joshuam1Best ResponseYou've already chosen the best response.0
216 cm^2 108 cm^2 54 cm^2 24 cm^2
 11 months ago

srossdBest ResponseYou've already chosen the best response.1
Well, with those choices, it's pretty obvious. It has to be less than 54. But still, try and work it out.
 11 months ago

Joshuam1Best ResponseYou've already chosen the best response.0
okay :D what is the first step?
 11 months ago

srossdBest ResponseYou've already chosen the best response.1
Square the scale factor,s ince you're working with area.
 11 months ago

srossdBest ResponseYou've already chosen the best response.1
Right. Now, you're going from post image to preimage, so you have to divide by that.
 11 months ago

Joshuam1Best ResponseYou've already chosen the best response.0
wait oops my mistake
 11 months ago

srossdBest ResponseYou've already chosen the best response.1
Are you doing 54/2.25?
 11 months ago

Joshuam1Best ResponseYou've already chosen the best response.0
sorry no i divded 54 and 3/2
 11 months ago

srossdBest ResponseYou've already chosen the best response.1
You need to divide by the squared ratio, since you're dealing with area.
 11 months ago

Joshuam1Best ResponseYou've already chosen the best response.0
ty for all your help I am done :D
 11 months ago
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