03.07 DBA Prep

Module 03 — Dilations and Similarity · quiz worth 30 pts

The big idea Prepare to explain Module 03 in your own words, with one scale-factor example and one proportion you can work aloud.

What the DBA is

The DBA is worth 30 points. Call or meet with the instructor and show that you can discuss Module 03. The instructor may also revisit Modules 01 and 02.

Afterward, submit the date of the conversation and the topics discussed. Read the Canvas rubric before the call.

This page is a checklist of ideas to put into your own words, not a script to read to the instructor.

Be ready to explain

  • Dilation: center, scale factor k, the origin rule (kx, ky), and how to find a center away from the origin
  • Similar versus congruent: corresponding angles match in both; sides are proportional versus equal
  • AA: two angle pairs are enough because the third angle follows from 180°
  • SAS similarity versus SAS congruence: proportional sides versus equal sides around an included angle
  • SSS similarity: one scale factor across all three side pairs
  • Triangle Proportionality and its converse
  • Altitude to the hypotenuse: three similar right triangles and the similar-triangle proof of the Pythagorean Theorem

Have one numerical example for k and one proportion you can work without notes. If one part is still shaky, ask about it during the call.