- A dilation takes a line not passing through the center of the dilation to a parallel line, and leaves a line passing through the center unchanged.
- The dilation of a line segment is longer or shorter in the ratio given by the scale factor.
Clusters should not be sorted from Major to Supporting and then taught in that order. To do so would strip the coherence of the mathematical ideas and miss the opportunity to enhance the major work of the grade with the supporting clusters.
TEST ITEM SPECIFICATIONS
This benchmark may be assessed using:
- Assessment Limits :
Items may use line segments of a geometric figure.
The center of dilation and scale factor must be given.
- Calculator :
- Clarification :
When dilating a line that does not pass through the center of dilation,
students will verify that the dilated line is parallel.
When dilating a line that passes through the center of dilation,
students will verify that the line is unchanged.
When dilating a line segment, students will verify that the dilated line
segment is longer or shorter with respect to the scale factor.
- Stimulus Attributes :
Items may give the student a figure or its dilation, center, and scale
and ask the student to verify the properties of dilation.
Items may be set in a real-world or mathematical context.
- Response Attributes :