Question

HELP PLEASE! WILL FAN AND GIVE MEDAL!

Which sequence of transformations produces an image that is not congruent to the original figure?

A. A translation of 4 units to the right followed by a dilation of 2
B. A rotation of 90 degrees clockwise followed by a translation of 2 units to the left.
C. A translation of 3 units to the left followed by a reflection across the y-axis
D. A reflection across the y-axis followed by a rotation of 90 degrees counterclockwise.

Answer 1

Mornin' Morgan =)

Ok so what does the original figure look like?

Answer 2

There isn't a original function. Just what is up there.

Answer 3

How do I show you which transformation does not produce an image that is congruent to an original figure.... without an original figure?

Answer 4

Nvm

Answer 5

assuming that the figure is in the first quadrant.
You are dilating the figure in option A, so it will change size and thus won't be congruent to the original one no matter where it is. Also it will be out of place just like in choices B and C
(where in B and C the figure isn't dilated by a scale factor of some number, and thus in B and C the figure remains the same size).
In D, you are reflecting the figure across the y-axis, and thus it will be in the 2nd quadrant, but to move it back, you will need to rotate the figure 90º clockwise, and NOT COUNTER-clockwise, since counterclockwise - 90º rotation makes it in the 3rd quadrant.

So in which option is the figure NOT CONGRUENT, just in A, where it is dilated to some scale factor.

Answer 6

Thank you soooooo much! A right?

Answer 7

Yes, A, since only there we are playing with the figure's size.

Answer 8

Anytime:)

Answer 9

Alright, thank you so much! c:

Answer 10

@SolomonZelman can you help me on a question again?

Answer 11

I can try at least;)

Answer 12

If a right triangle DEF is dilated by a scale factor of 2, which of the following statements is true?

A. Triangle DEF is similar to triangle D'E'F
B. The sides of DEF is congruent to the sides D'E'F
C. The angles of DEF is are congruent to the angles D'E'F
D. D'E'F is larger than DEF

Answer 13

When the triangle is dilated to a scale factor, then the dimensions increase but the proportions (of the sides to each other) don't change. Thus option A would be true.

Option B is definitely false, since after the dilation to any number (other than 1), the sides would NOT be congruent.

Option C is also good, because the angles remain the same, just that the size is different.
(Basically option A and C repeat each other, saying the same exact statement.)

Option D is true, D'E'F 's dimensions are exactly twice bigger than DEF 's .

Answer 14

ok so D! Thank you, a lot for helping!

Answer 15

Not just D, because A and C are also true.

Answer 16

The triangles are similar, because the angles haven't changed. (That gives A and C to be true)
And dilation to a number greater than 1, gives that D is true as well.

Answer 17

Ooooh, ok! I'll figure it out

Answer 18

alright...