Answer is BC=5
Step by step.
AB = 3
AC = 4
BC = x
If triangle is 90 degree at A, then AB and AC are two legs of the right triangle and BC is the hypotenuse. We use the Pythagorean theorem to find hypotenuse length.
a^2 + b^2 = c^2
3^2 + 4^2 = c^2
9 + 16 = c^2
25 = c^2
Take square root of both sides
5 = c
Problem solved
