Rotations
- Thread starter Camren
- Start date
Dr.Peterson
Elite Member
- Joined
- Nov 12, 2017
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I understand the question, and know the answer; but I don't know where you need help (or what help I could give that would help you figure out the answer yourself, as is our goal). Please tell us what you have tried, and what theorems you have learned that might be relevant.
The question is saying that B can be obtained by rotating A about P by 140 degrees, and can also be obtained by reflecting A first in a line PC and then in a line PD. That is, the rotation is equivalent to the pair of reflections. It asks for the angle between PC and PD.
You might have learned a theorem about this equivalence of transformations; of you might be expected just to sketch a figure of how the various lines and points would be related, and see what must be true of the two angles. (That is, to derive the theorem, in effect.) I can't tell what help you need without further information.
The question is saying that B can be obtained by rotating A about P by 140 degrees, and can also be obtained by reflecting A first in a line PC and then in a line PD. That is, the rotation is equivalent to the pair of reflections. It asks for the angle between PC and PD.
You might have learned a theorem about this equivalence of transformations; of you might be expected just to sketch a figure of how the various lines and points would be related, and see what must be true of the two angles. (That is, to derive the theorem, in effect.) I can't tell what help you need without further information.