In a right-angled triangle ABC, the angle C is a straight line. AB = 20 BC = 12. Find AC

In order to find what the leg AC is equal to, pay attention to the fact that triangle ABC is right-angled.
Thus, in order to find what the leg is equal to, one should use the Pythagorean theorem.
By the Pythagorean theorem, the square of the hypotenuse is equal to the sum of the squares of two legs.
Next, we write down the formula for the triangle ABC presented in the problem statement.
AB² = AC² + BC².
Now let’s express what the leg AC is equal to.
AC² = AB² – BC².
Next, we substitute the data in the condition for the values AB and BC.
AC² = 20² – 12².
AC² = 400 – 144.
AC² = 256.
AC² = 16².
AC = 16.
Answer: AC = 16.