Pie-charts - an introduction

Hi Margaritia. MA stands for the 'magic angle'. Many students forget to use this 'multiplier' to calculate the required angle. I've found it helps focus their thoughts before rushing into using the protractor. Also, 'MA' becomes 'MM', the 'magic multiplier'.
Cheers.
Ray

What does MA stand for?

Introduction? There's no introduction to Pie Charts, it starts in the middle with no explanation.