Describe when the interval is increasing, decreasing and constant?

Using d, e, and f as values on a triangle and d being 60 degrees, what is the value of e and f if d is 60 degrees? also, what do you notice about the values of e and f?

Aboat costs 19200 and decreases in value by 12% per year. how much will it cost in 5 years

Which expression can be used to determine the slope of the line that passes through the points -6, three and one, -9