## 16 Jan 2013

### MidWeek Maths Puzzle: A Problem With 12 Pins

Alice was helping her Granny Florence make a new dress. Well, Alice was not exactly helping, more like getting in the way.

"Very nice, dear, but please don't drop them on the floor as I need them to pin this dress."

"It has an area of 5... erm... pin units made from 12 pins."

"And don't stab yourself either!" Alice did not like being interrupted so carried on as if nothing had been said.

"And if I move these two pins I can make an area of 6 units squared.... and 7... and 8... and..."

"Yes, darling, I know you're very clever. Can you make an area of just 4 units?"

"Oh, that's too easy." And Alice laid out a square of 2 pins by 2 pins.

"No, I meant using all your pins."

Alice put on her thinking face. Florence was by no means a mathematician, but she knew how to keep a kid quiet and occupied.

The Question

Using all the 12 pins in the cross, rearrange them to enclose a shape with an area of 4 units squared.

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Maths Questions posted on Mondays and Wednesdays.
Prize Maths Questions (PMQs) posted on Fridays for a weekend challenge.

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Try this with toothpicks; marginally safer than pins or matches!

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