Question

Describe the sequence of transformations for which Triangle B is the image of Triangle A.

Answer 1

Answer:

• reflection in x = 1
• translation up 2

Step-by-step explanation:

The orientation of B is the opposite of the orientation of A, so a reflection is involved. The smallest angle is at the bottom in both figures, and the largest angle is on the right in A and the left in B, so the reflection is left-right, rather than up-down.

The point midway between the largest angle vertices is on the vertical line x=1, so that line can be used for reflection. Reflecting A across that line will put its large-angle vertex at (3, 0), so a translation up 2 units is also needed.

The reflection on x=1 and translation up 2 can be done in either order.

_____

Additional comment

A combination of reflection and translation is called a "glide reflection." Our choice of x = 1 as the line of reflection takes care of any horizontal translation that would be required if a different vertical line were used. For example, reflection across the y-axis would require a subsequent translation up 2 and right 2.

Answer 2

Answer:

2?

Step-by-step explanation: