Find the surface area

Asource of laser light sends rays ab and ac toward two opposite walls of a hall. the light rays strike the walls at points b and c, as shown below: what is the distance between the walls?

Afamily has two cars. the first car has a fuel efficiency of 25 miles per gallon of gas and the second has a fuel efficiency of 15 miles per gallon of gas. during one particular week, the two cars went a combined total of 1025 miles, for a total gas consumption of 55 gallons. how many gallons were consumed by each of the two cars that week?

Which rotation about its center will carry a regular hexagon onto itself