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Proving All Circles are SIMILAR

In the diagram below, you have two circles, circle A and Circle B. See if you can transform circle B so that it matches circle A exactly ("sits on" circle A). Use the horizontal and vertical sliders to move the center of the transformation of circle B (circle B'). Then, use the scale factor slider (sf) to adjust the radius of circle B'. Click the double arrows in the upper right corner to reset the activity with a new pair of circles. Do this 5 times. Then, answer the questions below the diagram.

1. Were you always able to match the circles?

2. Are circles always congruent? Explain why or why not, using your experiences in this activity.

3. Are circles always similar? Explain why or why not, using your experiences in this activity.

TRY THIS!

In our previous discussions, we talked about how to compute the scale factors between two circles that are dilated. Using the formula. Solve and answer the following questions below.

1.

2. Using your knowledge about similar circles, which of the following method is valid to prove that two circles are similar?

Select all that apply
  • A
  • B
  • C
  • D
Check my answer (3)