Answer: The correct answer is B. 7.
Explanation:
In a right triangle ABC, the hypotenuse AB is given as 25 units. The cosine of angle A, cos A, is given as 0.28. We need to find the length of side AC.
To solve this problem, we can use the cosine ratio, which relates the adjacent side to the hypotenuse of a right triangle. The cosine of an angle is defined as the ratio of the length of the adjacent side to the hypotenuse.
In this case, cos A = AC/AB. Substituting the given values, we have 0.28 = AC/25.
To solve for AC, we can cross-multiply and solve for AC: AC = 0.28 * 25 = 7.
Therefore, the length of side AC is 7 units.
The correct answer is B. 7.