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Using the State Curriculum: Mathematics, Grade 3

Algebra | Geometry | Measurement | Statistics | Probability | Number | Processes
Clarifications: Each clarification provides an explanation of the indicator/objective to help teachers better understand the concept. Classroom examples are often included to further illustrate the concept. While classroom examples could be shared with the students, the intended audience for the explanation/clarification is the classroom teacher-not the student. In addition, classroom examples may or may not reflect the assessment limits.

Standard 2.0 Knowledge of Geometry

Topic E. Transformations

Indicator 1. Analyze a transformation

Objective a. Identify and describe the results of a slide, flip, and turn

  • Use horizontal slide, flip over a vertical line, or turn of 90° clockwise around a given point of a geometric figure or picture

Clarification

A transformation is the movement of a plane figure to a new location without changing the size or shape (congruency) of the figure.

A slide (also known as a translation) is a horizontal, vertical, or diagonal, movement without turning, such as an elevator moving up or down. A slide provides a change in the location of the figure, but not its orientation, size or shape.

A flip (also known as a reflection) is the process of reflecting a figure across a line of symmetry creating a mirror or reflected image on the opposite side of the line. A common mistake is to flip without a line of reflection. This creates a coin flip where you literally turn the figure over. This is incorrect. In a flip or reflection, we are seeing the mirror reflection of the shape on the other side of the line of reflection. We are not turning it over. A flip changes the location and the orientation of the figure, but not its size or shape.

A turn (also known as a rotation) is the process of rotating, or spinning, a figure around a single point of rotation. At this grade level, the point of rotation is always a vertex of the figure. A turn changes the location and the orientation of the figure, but not it's size or shape. A turn is best demonstrated by holding the figure by a vertex and rotating the figure around the vertex.

Classroom Example

Slide (horizontal)

Flip (across a vertical line)

Turn (1/4 turn or 90 degrees clockwise)

Note: Transformations are best demonstrated using non-symmetrical figures

Classroom Example 1

Slide the figure 4 units right and 1 unit up. Draw the image on the grid.

Classroom Example 2

Identify the transformation performed.

1. Answer: Turn or Rotation

2. Answer: Flip or Reflection

3. Answer: Slide or Translation

Classroom Example 3

Describe which two transformations have taken place to move the figure from A to B.

Slide 7 units right. Horizontal flip.
or
Horizontal flip. Slide 7 units right.
/toolkit/vsc/clarification/mathematics/grade3/2E1a.xml
Resources for Objective 2.E.1.a:
CLARIFICATIONS | Sample Assessments |