## Engage NY Eureka Math 8th Grade Module 2 Lesson 1 Answer Key

### Eureka Math Grade 8 Module 2 Lesson 1 Exploratory Challenge Answer Key

a. Describe, intuitively, what kind of transformation is required to move the figure on the left to each of the figures (1)–(3) on the right. To help with this exercise, use a transparency to copy the figure on the left. Note: Begin by moving the left figure to each of the locations in (1), (2), and (3).

Answer:

Slide the original figure to the image (1) until they coincide. Slide the original figure to (2), and then flip it so they coincide. Slide the original figure to (3), and then turn it until they coincide.

b. Given two segments AB and CD, which could be very far apart, how can we find out if they have the same length without measuring them individually? Do you think they have the same length? How do you check? In other words, why do you think we need to move things around on the plane?

Answer:

We can trace one of the segments on the transparency and slide it to see if it coincides with the other segment. We move things around in the plane to see if they are exactly the same. This way, we don’t have to do any measuring.

### Eureka Math Grade 8 Module 2 Lesson 1 Problem Set Answer Key

Question 1.

Using as much of the new vocabulary as you can, try to describe what you see in the diagram below.

Answer:

There was a transformation, F, that moved point A to its image F(A) and point B to its image F(B). Since a transformation preserves distance, the distance between points A and B is the same as the distance between points F(A) and F(B).

Question 2.

Describe, intuitively, what kind of transformation is required to move Figure A on the left to its image on the right.

Answer:

First, I have to slide Figure A so that the point containing two dots maps onto the Image of A in the same location; next, I have to turn (rotate) it so that Figure A maps onto Image of A; finally, I have to flip the figure over so the part of the star with the single dot maps onto the image.

### Eureka Math Grade 8 Module 2 Lesson 1 Exit Ticket Answer Key

First, draw a simple figure and name it Figure W. Next, draw its image under some transformation (i.e., trace your

Figure W on the transparency), and then move it. Finally, draw its image somewhere else on the paper.

Describe, intuitively, how you moved the figure. Use complete sentences.

Answer:

Accept any figure and transformation that is correct. Check for the same size and shape. Students should describe the movement of the figure as sliding to the left or right, turning to the left or right, or flipping, similar to how they described the movement of figures in the exercises of the lesson.