A landscape architect is designing a square decorative plaza with an area of A A\,A square metres, where A=s2A = s^2A=s2 and the side length s s\,s is an integer. During a drainage calculation, it is found that A A\,A is a multiple of 5. Use the method of proof by contradiction to prove that s s\,s must also be a multiple of 5.
Practise AQA A Level Maths 1.4 A: Proof with exam-style questions for A Level Maths. 107 questions covering 1.4.1 Structure and methods of proof, matched to the AQA A Level Maths (7357) specification and written in Paper 1, Paper 2 and Paper 3 style. Every question includes a full worked solution and mark scheme, so you can see where marks are awarded rather than just whether you got the answer right.
