Answers

2014-01-07T18:44:39+08:00
These figures are symmetrical in relation to the dashed line. 
The line is called a symmetry line.This means that one half of the figure
is the mirror image of the other half.
              
Imagine that you folded the figure along the symmetry line.  Then both sides would exactly meet.
Or, place a mirror along the symmetry line. You see the other half of the figure reflected in the mirror.
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