Show how to bisect a line segment with a compass (no straight-edge).
Call the line segment AB.
Set compass to AB and make 2 circles around A and B.
Keeping the compasses at AB mark off the 120deg & 180deg points on the circle centred at B. Call the 180deg mark C.
Place the point of the compass at C and set the length to AC (i.e. 2AB). Swing an arc to cut the circle centred at A and call this intersection D.
Reset compass to length AB and place point at D. Inscribe an arc so that it cuts AB. This will be at M, the mid-point of AB.
Not as nice as Larry's solution, but it works...
|
|
Posted by Alec
on 2005-01-30 09:47:19 |
solution
