Why a2+b2=c2 and how to prove it in a simple way?
Only simple way to do it is by accurately drawing a right angled triangle on the board in your class then measuring the two shorter sides and substituting their values into the formula as a and b then square root the answer an check that it equals the hypotenuse (long side) Alternatively you could use a existing triangle and go backwards use 3^2+4^2=5^2 draw a triangle with sides of length 4, 3 and 5 and measure the angle opposite the longest side and it will be a right angle
