Originally posted by David113OK he we go ...
Given a circle, divide it into 4 equal arcs using only a compass.
Originally posted by wolfgang59Yes, compasses
OK he we go ...
1. Assuming you mean compasses and not compass.
2. Assuming we have a straight edge to hand.
Draw two circles (B & C) of equal diameter with centres on the circle in question (A). Draw a line through the points of intersection of B & C. This will be a diameter of A. Call the intersections of this diameter with A points x & y.
...[text shortened]... hich is orthogonal to the first diameter.
Hence the original circle is now exactly quartered.
Originally posted by AThousandYoungcompasses compassES !!!!
Make the compass radius equal to circle diameter by having it span the circle and then rotating it. If it has the same radius as the circle diameter, when rotated it will touch the circle only at one point, tangentially, and that will be the diameter. This gives you two points opposite one another, which splits the circle into halves.
Now, hang t ...[text shortened]... nt is halfway between the others. Use the compass to find it's opposite as with the first two.
Originally posted by AThousandYoungYou sure about that? Right-angled to approximately level will only give you approximately the highest point.
No need for a level. The horizontal state can be approximate. I'm relying on the pencil's base being perpendicular to it's shaft.
Originally posted by kcamsTwo problems:
Draw the circle, and carefully maintain the same radius.
Use the compass, with the same radius and mark a point anywhere on the circumference.
Draw line one, through the the point on the circumference and the centre point dividing the circle into equal lhalves.
Draw line two, now expand the compass, placing the point at the position where this dividin ...[text shortened]... the original centre
will perfectly divide the circle into four equal arcs.
edit for spelling