Will the quotient be positive or negative? -586/ 1234

I’m which figure is point g an orthocenter

Does the point (1, sqrt 7) lie on circle shown.

Acar started driving from city a to city b, distance between which is 620 miles, at a rate of 60 mph. two hours later a truck left city b and started moving towards city a at a rate of 40 mph. how many hours after the truck's departure will the two meet?