Question

Triangle BCD is dilated by a scale factor of 3 to form triangle B'C'D'. What is the measure of side DB? The numbers are 70, 76.8, and 84.

Answer 1

I don’t have the diagram, so I can’t pick the correct number yet. I need to know which side length given in the picture is the image (dilated) length that corresponds to DB.

Rule: under a dilation of scale factor 3, every side length in B'C'D' = 3 × (corresponding side length in BCD). So:
- If you are given a length from the dilated triangle B'C'D' and want DB (the original), divide that length by 3.
- If you are given a length from the original triangle BCD and want the dilated length, multiply by 3.

If the three choices (70, 76.8, 84) are the lengths of the dilated side corresponding to DB, then DB = (dilated length)/3:
- 70/3 ≈ 23.33
- 76.8/3 = 25.6
- 84/3 = 28

If instead those three choices are lengths of the original DB, then the corresponding dilated lengths would be:
- 70 → 210
- 76.8 → 230.4
- 84 → 252

Send the diagram or tell me which labeled side in B'C'D' corresponds to DB, and I’ll pick the correct choice.