




Massachusetts Comprehensive Assessment System
2011, Grade 10 Mathematics
Question 20: OpenResponse 

Reporting Category: Geometry Standard: 10.G.9  Draw the results, and interpret transformations on figures in the coordinate plane, e.g., translations, reflections, rotations, scale factors, and the results of successive transformations. Apply transformations to the solutions of problems. 
Triangle JKL is shown on the coordinate plane below. Copy the coordinate plane and triangle JKL as shown onto the grid in your Student Answer Booklet. Triangle JKL is reflected over the yaxis. On your grid, draw triangle J′K′L′, the image of triangle JKL after it has been reflected over the yaxis. Be sure to label the vertices.
Triangle J′K′L′ is rotated 90° clockwise about the origin. On your grid, draw triangle J″K″L″, the image of J′K′L′ after it has been rotated 90° clockwise about the origin. Be sure to label the vertices.
 Suppose the vertices of J″K″L″ are reflected over the yaxis and then reflected over the xaxis. Do the vertices of the resulting triangle have the same coordinates as the vertices of triangle JKL? Show or explain how you got your answer.

Scoring Guide and Sample Student Work Select a score point in the table below to view the sample student response.
Score  Description 
4 
The student response demonstrates an exemplary understanding of the Geometry concepts involved in drawing the results and interpreting transformations on figures in the coordinate plane. The student reflects and rotates a triangle on the coordinate plane and determines the relationship between the images and the original triangle. 
4 
3 
The student response demonstrates a good understanding of the Geometry concepts involved in drawing the results and interpreting transformations on figures in the coordinate plane. Although there is significant evidence that the student was able to recognize and apply the concepts involved, some aspect of the response is flawed. As a result the response merits 3 points. 
2 
The student response demonstrates fair understanding of the Geometry concepts involved in drawing the results and interpreting transformations on figures in the coordinate plane. While some aspects of the task are completed correctly, others are not. The mixed evidence provided by the student merits 2 points. 
1 
The student response demonstrates only minimal understanding of the Geometry concepts involved in drawing the results and interpreting transformations on figures in the coordinate plane. 
0 
The student response contains insufficient evidence of an understanding of the Geometry concepts involved in drawing the results and interpreting transformations on figures in the coordinate plane to merit any points. 
Note: There are 2 sample student responses for Score Point 4.
Grade 10 Mathematics
 Question 17: Number Sense and Operations
 Question 20: Geometry
 Question 21: Patterns, Relations, and Algebra
 Question 31: Patterns, Relations, and Algebra
 Question 41: Data Analysis, Statistics, and Probability
 Question 42: Measurement
Return to the MCAS 2011 Student Work Directory
Last Updated: February 1, 1997


