We did a performance task about dilation without the coordinate plane that was like the activity we did in the last block. It was collected for a grade.
Students learned the answers to the homework and made some observations about dilation in the coordinate plane (a multiply rule is always centered at the origin; corresponding sides are parallel, etc.)
We then did an investigation with triangles and patty paper that lead to the idea of triangle similarity shortcuts (AA, SAS, and SSS). Students understood that this is very much like the congruence shortcuts, only sides are proportional OR congruent.
HW #13 over these shortcuts is attached. Be sure to follow the instructions. Choices are multiple choice, but you must say what angles are congruent or what the proportion is between the sides.
Quiz Friday at the end of class over the basics of similarity and dilation; not over the new shortcuts.
Are these polygons similar? Why or why not based on definition. Find a missing side using similarity ratios. Name corresponding angles or sides. Dilate with or without the coordinate plane, locating center of dilation, knowing that sides will be parallel or collinear. Determine or use scale factor (similarity ratio).
Download below: homework, triangle shortcut investigation, dilation activity