How to set out a quadrant without a radius point?

Question

How do you half & quarter to set out a quadrant. I have forgot how to do it.

Answer 1

I'm assuming you're talking about cutting a circle into quadrants? This might be the long way to do it, but I would first find the center of the circle. Here's a web page for how to do that:

http://www.makeitsolar.com/science-fair-ideas/90-find-circle-center.htm

Then you draw your diameter. (there's half)

Finally, find and draw a line perpendicular to your diameter that crosses through the center of the circle.

Like I said - probably the long way to do it, but I'm a very visual person when it comes to geometry. I like to draw everything out.

Answer 2

Draw a chord. Construct the perpendicular bisector of the chord. This perpendicular bisector will pass through the centre of the circle, so you can use this as on of the 2 lines required to form a quadrant.

Where this line touches the circumference of the circle, again construct the perpendicular bisector of this line and you will have a second diameter that is 90 degrees to the first.

Voila! You have your quadrants.

Answer 3

Draw two chords and bisect each of them. Draw the perpendicular bisectors. Where they cross will be the centre of the circle. Draw a straight line through the centre. You have now divided the circle into two equal halves. Construct and draw the perpendicular bisector of the diameter. You have divided the circle into 4 equal quarters and hence have your quadrants.