Question 23

Question 23 A transformation is applied to ∆ABC to form ∆DEF (not shown). Then, a transformation is applied to ∆DEF to form ∆GHJ The students should not need to use calculators for this problem. They will need to create a transformation on their graph and then describe what is happening to it. The following slides will be one per part.

Question 23 Part A Graph ∆DEF on the xy-coordinate plane. In order for the triangle to get to looking like GHJ, it first needs to be flipped over the Y-axis. Because of this, the triangle will be reflected over the Y-axis. A reflection of the y-axis means that shape looks like it is looking in a mirror and the mirror image is reflected.

Question 23 Part B Describe the transformation applied to ∆ABC to form ∆DEF. The transformation that took place was that there was a reflection over the y-axis The students just needed to state that there was a reflection over the y-axis to show in order to form the new triangle DEF.

Question 23 Part C Describe the transformation applied to ∆DEF to form ∆GHJ. The triangle was dilated by a scale factor of 2.5 The students will have to state how the triangle got so big. All of the numbers were scaled by 2.5. This means that they were multiplied by 2.5. In order to figure that out, the students could divide the GHJ points by the DEF points to figure out the scale factor.

Question 23 Part D Select one statement that applies to the relationship between ∆GHJ and ∆ABC. □ ∆GHJ is congruent to ∆ABC □ ∆GHJ is similar to ∆ABC □ ∆GHJ is neither congruent nor similar to ∆ABC In order for the students to do well on this problem, they will need to know what congruent and similar mean. Congruent means that the triangles are going to be the same size and shape. Similar means that the triangles are the same shape but not the same size. Based on these definitions, the triangles are similar to each other. Their sizes just vary from each other