Answers

2016-02-06T09:42:56+05:30
If the compass is changed than the value which we have taken by the compass will be changed and the perpendicular bisector construction will be incorrect
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2016-02-06T11:21:18+05:30
If the setting of the compass is changed, then the arcs made by it wont intersect each other at all.Hence construction of the perpendicular bisector would not be possible.

hope it helps and pls mark dis as best answer :)
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