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Sunday Afternoon Maths LXWhere is Evariste?
Bending a Straw
Sunday Afternoon Maths LIXTurning Squares
Sunday Afternoon Maths LVIIIFactorial Pattern
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Bending a Straw
Two points along a drinking straw are picked at random. The straw is then bent at these points. What is the probability that the two ends meet up to make a triangle?
Two players take turns placing identical plates on a square table. The player who is first to be unable to place a plate loses. Which player wins?
Earlier this year, I wrote a blog post about different ways to prove Pythagoras' theorem. Today's puzzle uses Pythagoras' theorem.
Start with a line of length 2. Draw a line of length 17 perpendicular to it. Connect the ends to make a right-angled triangle. The length of the hypotenuse of this triangle will be a non-integer.
Draw a line of length 17 perpendicular to the hypotenuse and make another right-angled triangle. Again the new hypotenuse will have a non-integer length. Repeat this until you get a hypotenuse of integer length. What is the length of this hypotenuse?
The number of degrees in one internal angle of a regular polygon with 360 sides.
What is the volume of the smallest cube inside which a rectangular-based pyramid of volume 266 will fit?
What is the maximum number of lines that can be formed by the intersection of 30 planes?
Cross Diagonal Cover Problem
Source: Gaurish Korpal
Draw with an \(m\times n\) rectangle, split into unit squares. Starting in the top left corner, move at 45° across the rectangle. When you reach the side, bounce off. Continue until you reach another corner of the rectangle:
How many squares will be coloured in when the process ends?
The diagram shows two semicircles.
\(CD\) is a chord of the larger circle and is parallel to \(AB\). The length of \(CD\) is 8m. What is the area of the shaded region (in terms of \(\pi\))?