In the triangle ABC of the side AB = 6 cm BC = 8 cm, the angle B = 90 degrees. find AC.

Since the angle B = 90 degrees, the side of the triangle ABC AC is the hypotenuse, because it lies opposite the angle equal to 90 degrees.
By the Pythagorean theorem, we find the length of the AС:
AC ^ 2 = AB ^ 2 + BC ^ 2;
AC = √ (AB ^ 2 + BC ^ 2);
AC = √ (6 ^ 2 + 8 ^ 2);
AC = √ (36 + 64);
AC = √100;
AC = 10 cm.
Answer: AC = 10 cm.