How can you use the fact that m 4 + m 1 + m 5 -=180 to show that m 2 + 1 +3 = 180

Really need on these. i have no idea what to do

The map shows the location of the airport and a warehouse in a city. though not displayed on the map, there is also a factory 112 miles due north of the warehouse. a truck traveled from the warehouse to the airport and then to the factory. what is the total number of miles the truck traveled?

If the tip varies directly with the number of guest which equation represents between the tip, t, and the number of guest, g?