Today Puzzle #770
Puzzle No. 770鈥� Friday 26 June
Sunday is commemorated by mathematicians as Tau Day. Tau or 2 pi is the ratio between the circumference of a circle and its radius, approximately 6.28 and the 28th June can be written as 6/28 in the American calendar system. To celebrate Tau Day and the end of Maths Week London, you order a pizza. In terms of surface area, which is larger: an 18 inch pizza or two 12 inch pizzas?
Today’s #PuzzleForToday has been set by Bobby Seagull and fellow maths teacher Susan Okereke, who are both co-hosts of the Maths Appeal podcast.
Click here for the answer
The 18 inch pizza has counter intuitively more pizza!
Area of a circle is pi x radius x radius
Area of 18 inch pizza = pi (18/2)^2 = 81 pi inches squared
Area of 12 inch pizza = 2pi (12/2)^2 = 72 pi inches squared
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