Difference of two squares, staple diet for GCSE maths students, is first proposition in Carr’s book of magic and has ancient geometric roots in Euclid Book II.
Mechanics 1, June 2007 paper, now written out and available at http://jped.co.uk/ExamBucket/examfiles/M1Sum07W.pdf
A rectangle which can be divided into a square and a smaller similar rectangle has length and breadth in the Golden Ratio
Back in the classroom after Easter for Mechanics 1 consolidation and revision.
Carr’s 626, in his magical book for Edwardian mathematical autodidacts, provides summary of general solutions for trigonometrical equations useful to STEP and A level students.
Friendly triangles – good visual method for memorising trig ratios of 30, 45 and 60 degree angles. Known for thousands of years as per the Babylonian tablet