One of the legs of a right triangle measures 3 cm and its hypotenuse measures 4 cm. Find the measure of the other leg. If necessary, round to the nearest tenth.

From the pythogoras theorem where the sum of the squares of the legs of a right triangle is equal to the square of the hypotenuse we have : 4^2=3^2 + x^2
we rearrange the formula to get :
16 - 9 = x^2 leaving x= square root of 7.