Getting Started 
Misconception/Error The student makes significant errors when graphing points in the coordinate plane. 
Examples of Student Work at this Level The student:
 Reverses the x and yaxes, reverses x and ycoordinates, or interchanges the positive and negative portions of the axes.
 Graphs some or all of the vertices incorrectly.

Questions Eliciting Thinking On a coordinate plane, which is the x and which is the yaxis? In an ordered pair, which is the x and which is the ycoordinate?
Where did you start counting? Which direction did you move to graph the xvalue and which direction did you move to graph the yvalue?
Can you show me how you graphed the vertices?
What type of figure did you graph? Does it look like a polygon? 
Instructional Implications Review graphing points in the coordinate plane. Be sure to include points in all four quadrants and on both axes. Ask the student to both graph points given their coordinates and to give the coordinates of graphed points. Consider implementing the CPALMS Lesson Plan Chameleon Graphing (ID 5728). Provide the student with additional opportunities to graph specified figures given the coordinates of their vertices.
Define a polygon as a closed figure with three or more sides. Show the student examples and nonexamples of polygons. Provide the student with additional opportunities to graph polygons in all four quadrants, with integer and rational number coordinates. Clarify for the student the correct way to name points, line segments, and polygons. Remind the student that the order the points are listed indicates the order of the vertices in the polygon. 
Moving Forward 
Misconception/Error The student is unable to determine the area of the polygon. 
Examples of Student Work at this Level The student correctly graphs the polygon but:
 Miscounts when attempting to find the length and width of the rectangle.
 Miscounts when attempting to count each square unit inside the polygon.
 Determines the perimeter instead of the area.

Questions Eliciting Thinking What is the length of each side of the rectangle? Can you show me how you counted? Did you count the grid lines or the unit lengths?
How can you determine the dimensions of the graphed figure?
What is the difference between perimeter and area of a rectangle? What is the formula for finding area of a rectangle? 
Instructional Implications Review the concept of length and give the student opportunities to find lengths on a number line by counting unit lengths. Relate finding length on a number line to using a ruler. Explain how vertical and horizontal lengths are measured in the coordinate plane. Directly address the misconception that length is calculated by counting notches or grid lines or that length can be negative. Emphasize the meaning of the unit length by providing a unit of measure such as centimeters. Eventually transition the student to calculating distances (rather than counting unit lengths) between points with the same first coordinate or the same second coordinate on a coordinate plane. Guide the student to use absolute value symbols to represent lengths [e.g., represent the distance between (7, 2) and (2, 2) as 7 – 2 = 9 = 9].
If needed, review the difference between the area and perimeter of a figure. Offer the student additional opportunities to calculate both area and perimeter of figures graphed on the coordinate plane. At this point, consecutive vertices should have the same xcoordinates or the same ycoordinates.
Model showing work in an appropriate written form. Guide the student to find and label each length and to clearly show how the area is calculated by writing an equation such as A = 9 × 3 = 28 square units. Encourage the student to complete all computational work on the side so that it is not the focal point of the written communication of the method of solution. 
Almost There 
Misconception/Error The student does not completely show work to justify the answer, makes a minor error, or does not label the area using the correct units of measure. 
Examples of Student Work at this Level The student:
 Does not include any units of measure.
 Represents lengths as negative values.

Questions Eliciting Thinking Your answer is numerically correct but what unit of measure should you use?
What is the difference between 28 units and 28 square units?
How did you determine the base and height of the rectangle? Did you need to determine the length of all four sides in order to determine the area? Explain.
Is it possible for a length to have a negative value? 
Instructional Implications Provide feedback to the student concerning any errors made. Allow the student to revise his or her work.
If needed, review the difference between linear units and square units (e.g., feet and square feet). Clarify that units written as are read as “square inches.” Model the difference between four linear units and four square units using graph paper.
Explain that length (distance between points) is typically represented by a nonnegative value. Guide the student to represent distances on both the number line and in the coordinate plane using absolute value symbols [e.g., represent the distance between (7, 2) and (2, 2) as 7 – 2 = 9 = 9]. Provide the student with additional opportunities to represent distances between points with the same x or ycoordinates.
If needed, model showing work in an appropriate written form. Guide the student to find and label each length and to clearly show how the area is calculated by writing an equation such as A = 9 × 3 = 28 square units. Encourage the student to complete all computational work on the side so that it is not the focal point of the written communication of the method of solution. 
Got It 
Misconception/Error The student provides complete and correct responses to all components of the task. 
Examples of Student Work at this Level The student graphs the rectangle correctly, determines the length of the base (9 units) and height (3 units), and uses the dimensions to determine the area of the rectangle as 28 square units. 
Questions Eliciting Thinking Why does using the area formula give you the same number of square units of area as counting the number of unit squares inside the rectangle?
Can you determine the perimeter of the rectangle? How would you determine the perimeter of the rectangle using only the coordinates of the vertices and not the graph? 
Instructional Implications Challenge the student to determine the perimeter (or area) of a rectangle (or square) without graphing the coordinates when given coordinates having the same first coordinate or the same second coordinate.
Consider implementing the MFAS task Fence Length (6.G.1.3), which involves determining the perimeter of a composite figure. 