The coke machine in college takes 50 pence pieces. It also takes a certain foreign coin of traditional design...
The area of a regular pentagon looks about twice as a big as the pentangle star drawn within it. Is it?
Three points A, B and C lie in this order on a line, and P is any point in the plane. Use the Cosine Rule to prove the following statement.
Choose some dimensions to try for the table.
Draw a rectangle on paper to represent each table, and try out some angles.