Symmetry
problem
Encircling
An equilateral triangle is sitting on top of a square.
What is the radius of the circle that circumscribes this shape?
problem
Rhombicubocts
Each of these solids is made up with 3 squares and a triangle around each vertex. Each has a total of 18 square faces and 8 faces that are equilateral triangles. How many faces, edges and vertices does each solid have?
problem
Angular reflection
Weekly Problem 28 - 2013
Two lines meet at a point. Another line through this point is reflected in both of these lines. What is the angle between the image lines?
Two lines meet at a point. Another line through this point is reflected in both of these lines. What is the angle between the image lines?
problem
Prime magic
Place the numbers 1, 2, 3,..., 9 one on each square of a 3 by 3 grid so that all the rows and columns add up to a prime number. How many different solutions can you find?
problem
Symmetric trace
Points off a rolling wheel make traces. What makes those traces
have symmetry?
problem
Square pizza
Can you show that you can share a square pizza equally between two
people by cutting it four times using vertical, horizontal and
diagonal cuts through any point inside the square?