Since segment XZ is perpendicular to segment WY, angles WZX and XZY are both right angles and congruent. The proportion shows the corresponding sides are proportional, so the triangles are similar by the SAS Similarity Postulate.

6 over 12 equals 3 over 6
6 over 3 equals 6 over 12
6 over 6 equals 3 over 12
12 over 6 equals 3 over 6

This is most definately an impulse purchase because Ronnie had not planned to buy the stereo speaker, but had a impulse to buy it even  when he didn't have the money. Had he already decided he wanted the stereo and went to the store to buy it that would not be an impulse purchase it would be a planned purchase.

hope this helps mark me brainliest if it helped