Three punctuation marks as shown in the following figure should be drawn on the placard of a development zone: period, comma and question mark. It is known that the radius of the big circle is r and t

Three punctuation marks as shown in the following figure should be drawn on the placard of a development zone: period, comma and question mark. It is known that the radius of the big circle is r and the radius of the small circle is r. Area of the period: π (4R2-R2) = 3π R2;

Area of comma: π×4 R2÷2 = 2πR2；;

Area of question mark: 34π (4R2-R2)+π R2 =134π R2;

Because 13 4 πr 2 is the largest,

Therefore, the pigment of the question mark is much used.