Answer:
The required equation is
.
Step-by-step explanation:
Consider the provided information.
The Initial value of poster = $ 18
After 1 year amount of increase = $ 20.70
With the rate of 15% = 0.15
Let future value is y and the number of years be x.

Now verify this by substituting x=1 in above equation.

Which is true.
Hence, the required equation is
.
X = 20 degrees
Y = 30
This is acute triangle so all the sides and angles are the same. Subtract 16 from 46 and you receive 30 for y. For the corresponding angle, subtract 80 from 180. Then add 60 to that and subtract that from 180 for x.
I think it’s 236.8 correct me if I’m wrong?