115 degrees because there are 180 degrees in a triangle so let the missing angle in the trinagle be x. Then we have x+75+40=180. Solving for x and subtracting that from 180 (supplementary angles) we get 115 degrees.
3,500 kilometers in one day
18 square units should be the right answer
I assume a unit rate is simply ms^-1 or whatever.
In order to determine m/s one must make the "per whatever" part equal to 1. In this case it is seconds, so we must make seconds equal to 1.
If in 17 seconds it travels 238 metres, that means in 1 second it travels 238/17m=14m
Therefore the unit rate (speed) of the car is 14m/s or 14ms^-1