In triangle ABC, angle C is 90º, AB = 12, sinA = 0.25. Find the length of the smaller leg of the triangle.

Since the angle С is equal to 90º, then the triangle ABC is right-angled with the hypotenuse AB, then the following equality is true:
BC = AB * sin (A) = 12 * 0.25 = 3.
Using the Pythagorean theorem, we find the second leg:
AC ^ 2 = AB ^ 2 – BC ^ 2 = 12 ^ 2 – 3 ^ 2 = 135;
AC = √135.
It’s obvious that:
BC <AC.
Answer: the smallest leg of the triangle is 3.