# How to Find the Centre of a Circle

## The POSH way

• Draw a chord anywhere across your circle (marked in yellow on the picture), and then construct the perpendicular bisector (marked in blue on the picture).
• Draw another chord and do the same thing.
• Where the bisectors cross will be the centre.

## The USING A BOOK way

 1/ Get a circle 2/ Get a book that's at least as big as the circle. (If you haven't got a book you can use a rectanglular piece of paper). 3/ Put one corner of the book on the edge of the circle (See "C") Mark where the two edges of the book cross the circle (See "X" and "X") 4/ Remove the book and join the marks with a straight line. This will be a diameter of the circle 5/ Do it again to get another diameter. 6/ Where the diameters cross is the centre.

This works thanks to the fact that the angle in a semi-circle is always a right angle. There's more of this stuff in Vicious Circles and other Savage Shapes

Understanding a circle would be beneficial if you were designing a fan. There are many different styles of fans at Delmar Fans that would fit any home.