Verify that dilations send non-center-passing lines to parallel lines and leave center-passing lines unchanged.
Use dilation to reason about parallel relationships in a figure
Problem
In triangle \(ABC\), a dilation centered at \(A\) maps segment \(BC\) to \(B'C'\). What conclusion about the image line or segment follows from the dilation?
The line-image theorem depends on whether the source side’s supporting line contains the dilation center. We’ll identify the center and source line, use the triangle’s noncollinearity to settle incidence, apply the invariant-or-parallel rule, and transfer the supporting-line result to the segment joining the corresponding image endpoints.
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