You need to provide the last question. There isn’t enough information to help you. I’m sorry
Answer:
Area = π r^2.
Step-by-step explanation:
Given the radius r of a circle, the area = π r^2.
So for example the area of a circle of radius 2 = π 2^2
= 4π.
(2.7, 2.3)
(2, 1.7)
(1.7, 1.3)
again may be wrong
For this case we must solve the following equation:

To solve we follow the steps below:
We square both sides of the equation squared:

We choose the positive value because we talk about $. 
Answer:
$6
1. 4.47 x 10^3
2. 4.8 x 10^8