Welcome to your interview.
The question is on your right: Distance From Point to Line. Take a moment with it first.
Talk your thinking through with me if you like - when you're confident, submit your answer and I'll grade it like a real screen (7/10 or better passes). Discussion and graded submissions share your five interviewer interactions, so spend them well.
Given two points in a 2D plane representing a vehicle's path, write a C++ function to determine the line equation and calculate the perpendicular distance from a third point to that line.