HiSET: Math : Understand transformations in the plane

Study concepts, example questions & explanations for HiSET: Math

varsity tutors app store varsity tutors android store

Example Questions

Example Question #104 : Hi Set: High School Equivalency Test: Math

On the coordinate plane, let and be located at and , respectively. Let be the midpoint of and let be the midpoint of . On the segment, perform the translation . Where is the image of located?

Possible Answers:

Correct answer:

Explanation:

The midpoint of a segment with endpoints at  and is located at

Substitute the coordinates of  and  in this formula to find that midpoint of is located at

, or .

Substitute the coordinates of and to find that midpoint of is located at

, or .

To perform the translation , or, equivalently,

,

on a point, it is necessary to add

to its -coordinate, and

to its -coordinate.

Therefore, the -coordinate of the image of  under this translation is

;

its -coordinate is

The image of is located at .

 

 

Example Question #2 : Translations

Consider regular Hexagon .

On this hexagon, perform the translation . Then reflect the hexagon about . Let  be the image of  under these transformations, and so forth.

Which point on Hexagon  is the image of  under these transformations?

Possible Answers:

Correct answer:

Explanation:

The translation  on a figure is the translation that shifts a figure so that the image of , which we will call , coincides with . All other points shift the same distance in the same direction. Below shows the image of the given hexagon under this translation, with the image of  marked as :

1

If the image is reflected about , the new image is the original hexagon. Calling  the image of  under this reflection, we get the following:

1

 

, the image of  under these two transformations, coincides with .

Example Question #7 : Translations

Consider regular Hexagon .

On this hexagon, perform the translation . Then perform a  rotation on the image with center at . Let  be the image of  under these transformations, and so forth.

Which of the following correctly shows Hexagon  relative to Hexagon ?

Possible Answers:

Hexagons

Hexagons

Hexagons

Hexagons

Hexagons

Correct answer:

Hexagons

Explanation:

The translation  on a figure is the translation that shifts a figure so that the image of , which we will call , coincides with . All other points shift the same distance in the same direction. Below shows the image of the given hexagon under this translation:

1

If this new hexagon is rotated clockwise  - one third of a turn - about , and call  the image of , and so forth, the result is as follows:

1

Removing the intermediate markings, we see that the correct response is 

Hexagons

Example Question #111 : Hi Set: High School Equivalency Test: Math

Consider regular Hexagon .

On this hexagon, perform the translation . Then perform a  rotation on the image with center at 

Let  be the image of  under these transformations,  be the image of , and so forth. Under these images, which point on the original hexagon does  fall?

Possible Answers:

Correct answer:

Explanation:

The translation  on a figure is the translation that shifts a figure so that the image of  coincides with . All other points shift the same distance in the same direction. Below shows the image of the given hexagon under this translation, with  the image of :

1

If this new hexagon is rotated  - one half of a turn - about  - the image is the original hexagon, but the vertices can be relabeled. Letting  be the image of  under this rotation, and so forth:

1

 coincides with  in the original hexagon, making  the correct response.

Example Question #1 : Translations

On the coordinate plane, let , , and be located at the origin, , and . Construct the median of  from and let the foot of the median be . On the triangle, perform the translation . Where is the image of ?

Possible Answers:

Correct answer:

Explanation:

By definition, a median of a triangle has as its endpoints one vertex and the midpoint of the opposite side. Therefore, the endpoints of the median from are itself, which is at , and , which itself is the midpoint of the side with origin  and , which is , as its endpoints.

The midpoint of a segment with endpoints at  and is located at

,

so, substituting the coordinates of and in the formula, we see that is

, or .

See the figure below:

1

To perform the translation , or, equivalently,

,

on a point, it is necessary to add

and

to the - and - coordinates, respectively. Therefore, the image of  is located at 

,

or

.

Example Question #51 : Measurement And Geometry

Consider regular Hexagon .

On this hexagon, perform the translation . Then perform a  clockwise rotation on the image with center at 

Let  be the image of  under these transformations,  be the image of , and so forth. Under these images, which point on the original hexagon does  fall?

Possible Answers:

Correct answer:

Explanation:

The translation  on a figure is the translation that shifts a figure so that the image of  coincides with . All other points shift the same distance in the same direction. Below shows the image of the given hexagon under this translation, with the image of  marked as :

1

If this new hexagon is rotated clockwise  - one third of a turn - about  - the image is the original hexagon, but the vertices can be relabeled. Letting  be the image of  under this rotation, and so forth:

1

 coincides with  in the original hexagon, making  the correct response.

Example Question #1 : Rotations

What is the result of rotating the point  about the origin in the plane by ?

Possible Answers:

Correct answer:

Explanation:

Rotating a point 

geometrically in the plane about the origin  is equivalent to negating the coordinates of the point algebraically to obtain

.

Thus, since our initial point was

we negate both coordinates to get

as the rotation about the origin by .

Example Question #114 : Hi Set: High School Equivalency Test: Math

Nonagons

Examine the figures in the above diagram. Figure 2 is the result of performing which of the following transformations on Figure 1?

Possible Answers:

Correct answer:

Explanation:

The diagram below superimposes the two figures:

Nonagons

The transformation moves the black diagonal to the position of the red diagonal, and, consequently, points  and  to points  and , respectively. This constitutes two-tenths of a complete turn clockwise, or a clockwise rotation of 

Example Question #1 : Rotations

Question mark

Rotate the above figure  counterclockwise. Which figure is the result?

Possible Answers:

Question mark

Question mark

None of the other choices gives the correct result.

Question mark

Question mark

Correct answer:

Question mark

Explanation:

A counterclockwise rotation of  is  ofa complete rotation. Observe the following diagram:

Question mark

In the right figure, the question mark has been turned one-eighth of a complete turn counterclockwise. This is the correct orientation.

Example Question #1 : Rotations

Hexagon

Let  and  be the midpoints of  and , respectively.

Rotate the above hexagon  clockwise, then reflect it about the line through . Call  the image of  after these transformations.

 will be located in the same position as which of the following points?

Possible Answers:

Correct answer:

Explanation:

 rotation is equivalent to  of a complete rotation, so rotate as follows:

Hexagon

The image of  under this rotation, which we will call , is at .

Now, locate the midpoints  and , and construct the line  as described and shown below. Perform the reflection:

Hexagon

It can be seen that the image of  under this transformation - the desired  - is located at .

Learning Tools by Varsity Tutors