POINT A   point   in   geometry   is   not   really   anything   but   some location   or   position   in   space.   It   has   no   width, length   or   depth.   A   point   or   dot   on   a   piece   of   paper has   some   size   to   it   but   in   geometry   there   is   no size   to   it.   An   intersection   of   two   lines   could establish a point. LINE: For   geometric   purposes   we   will   define   a   line   as   an infinite   straight   line   extending   in   two   directions.   A line   has   length   but   no   width   nor   thickness.   Let   me define   this   for   you.   When   we   draw   a   line   with   a   pen   it has   width   because   we   can   see   it   and   you   could   measure it.   It   is   the   same   width   as   the      tip   on   the   pen.   No matter   how   thin   of   a   pen   you   are   using   it   still   has some   dimension   to   it.   But   in   geometry   this   line   would actually   be   invisible   to   our   eyes because   it   is   defined   as   only having   length   (no   thickness   nor width.   Through   two   given   points one   and   only   one   straight   line can be drawn. LINE   SEGMENT:   A   section   of   line   between   two end    points.    This    is    also    the shortest    distance    between    two points.    In    sheet    metal    line segments   are   what   we   always   work with. RAY: Portion    of    line    bound    in    one direction   by   an   end   point   and extending   in   the   other   direction indefinitely. PERPENDICULAR   LINES:   Lines   which   intersect   at right angles.(90 degrees) PARALLEL   LINES:   In   a   plane,   lines   which   cannot   meet,   however   far they   may   extend.   The   line,   line   segment   and   ray   below are all parallel to each other.  LINE  RAY  LINE SEGMENT Back to:
A practical use for a ray in sheet metal development could be  extending the outer surfaces of an acute angle to where they intersect (apex)
Please Donate if you find this site helpful. Thank-You!
No part of this publication may be reproduced, or transmitted, or stored, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise, without the prior written permission of, Sixth Edition Reformatted for Internet, ©2012