Question

Concentric circles with center G have radii 5 and 11 as shown.

2 concentric circles with center G are shown. The smaller circle has a radius of 5 and the larger circle has a radius of 11.

Which would prove that the circles are similar?

Dilate the smaller circle by a factor of
.

If the circles were not concentric, what additional step would be needed to prove they are similar?


one of the circles so that the circles have the same center.

Answer 1

Dilate the smaller circle by a factor of 11/5 (centered at G).

If the circles were not concentric, first translate (move) one circle so the centers coincide, then dilate.