Overview: Students to be able to define and identify dilations and similar figures, identify scale factors, describe the changes to x and y coordinates of a figure after a dilation, and describe a sequence of transformations that determine whether two figures are similar.
Essential Question: Students will investigate dilations and similarity; they make connections between scale factors and dilation factors and define similar figures. Students dilate figures on the coordinate plane using different locations for the center of dilation and generalize the coordinates of images formed from a dilation with a center at the origin. Then they identify a sequence of transformations that map from a figure to a similar figure.
Standards: CCSS: 8.G.3 & 8.G.4
Standards: CCSS: 8.G.3 & 8.G.4
Classroom Activities/Resources:
Resources: nearpod, calculators, notebooks
Activities:
o Day 1:
Scale drawings by doing
Dilating figures with a scale factor greater than 1
o Day 2:
Dilating figures with a scale factor less than 1
o Day 3:
Creating and verifying similar figures
Formative assessment
o Day 4:
The escalator or the stairs
Scaling up and down on the coordinate plane
o Day 5:
Using the origin as the center of dilation
Using a point on a figure as the center of dilation
o Day 6:
Using a point inside or outside a figure as the center of dilation
Formative assessment
o Day 7:
Same figure or same shape
Proving similarity through dilations
o Day 8:
Proving similarities through transformations
o Day 9:
Comparing images
Formative assessment
o Day 10:
Unit assessment