This could be calculated using the proportion. If the value of the car decreases by 15% each year, that means that after each year the value of the car is 85% of the value from the first year.
Corresponding angles are angles that are in the same relative position to both the parallel line they are on and the transversal. In this case, SQU and WRS are both above the parallel line they are on and on the same side of the transversal; this makes them corresponding angles. This also means it is the corresponding angles postulate.
