Today's PUZZLE CLASSIC OF THE DAY
PREVIOUS 12 DAYS
Grinder: 2 Congruent Parts

Cut this figure into 2 congruent parts (identical in area and shape, though they can be mirrored).
What Day?
If two days ago was the day preceding Tuesday, what day will be the day after tomorrow?
Age of Spouses
A married woman states: "My husband's age is a two-digit number, which, when digits are swapped, gives my age. He is older than me and our age difference is 1/11th of our ages' sum." How old are the spouses?
Four 5's to 16

Using some arithmetic operations, convert four 5's into 16.
Cutout & Hole: 2 Congruent Parts

Cut this figure into 2 congruent parts (identical in area and shape, though they can be mirrored).
Spiral: 2 Congruent Parts

Cut this figure into 2 congruent parts (identical in area and shape).
TriCounting: 5 Rotating Squares

How many triangles are in this figure? Select a triangle and click the "Count" button.
Circle Relationship
One circle is circumscribed around a square. Another circle is inscribed within the same square. Using 2's and r's, show the ratio between the circles' areas.
TriCounting: M in Triangle

How many triangles are in this figure? Select a triangle and click the "Count" button.
A Bottle's Volume
If a bottle, partly filled with liquid, has a round, square, or rectangular bottom which is flat, it is possible to find its volume using only a ruler. What would be critical in achieving it?
Six Glasses Problem
Place 6 glasses on a table - 3 up, 3 down. Take any pair of glasses and invert them. If you continue to invert the pairs as long as you like, in how many moves would you end up with all six glasses upright?
Hoover: 2 Congruent Parts

Cut this figure into 2 congruent parts (identical in area and shape).