Answer: 30°.
- A 15°
- B 30°
- C 45°
- D 60°
Correct answer: B. 30°
Explanation: Slopes correspond to inclinations 60° and 30°, so the acute angle between them is 30°.
The slope of a line is the ratio of vertical change (rise) to horizontal change (run) between any two points on it - equivalently, the tangent of the angle θ the line makes with the positive x-axis.