1 Using straight edge and compasses only (i.e. no measuring with a ruler or protractor), construct: (a) the perpendicular bisector of a line segment; (b) the bisector of an acute angle; (c) an equilateral triangle. Explain the geometrical principles that ensure your constructions work.

Question

1	Using straight edge and compasses only (i.e. no measuring with a ruler or protractor), construct: (a) the perpendicular bisector of a line segment; (b) the bisector of an acute angle; (c) an equilateral triangle. Explain the geometrical principles that ensure your constructions work.

anonymous · Answer

just want an explanantion of the geometrical principles

anonymous · Answer

i know how to construct them

phi · Answer

see http://www.mathopenref.com/constbisectline.html for (a) scroll down to proof for why it works. you can search the site for the other constructions.

anonymous · Answer

Thanks @phi

anonymous · Answer

is the explanation suitable to teach 11-16 year olds? that's who the target audience if for @phi

phi · Answer

16 year old is almost college age...
If they understand geometric proofs, yes.  But you will have to be the judge.

anonymous · Answer

okay thanks 
@phi