A right angled triangle has sides of length 3 and length 4, what is the length of the hypotenuse?

using pythagorus ( c^2 = b^2 + a^2) and plugging in 3 and 4 as a and b we get c^2 = 3^2 + 4^2 = 9 + 16 = 25. Taking the positive square root as sides can't be negative we get c = 5