Simple, first change the 4.5% into 0.045
Thus,
900=0.045*n
900/0.045=0.045n/0.045
20,000=n
Thus, your answer is 20,000.
To find the original price before the increase, divide the new price by 1 + the percent of increase.
198 / 1.20 = 165
The original price was $165
1/3 is the slope, or 1 over 3.
Your answer will be a repeating decimal or fraction
54.333
54 1/3
The formula of an area of a circle:

r - a radius
We have r = 14m. Substitute:

If you want an approximate area, you can accept 
Then:
