Answer: 
<u>Step-by-Step Explanation:</u>
Pythagorean Theorem is: a² + b² = c² , <em>where "c" is the hypotenuse</em>

Note: (15)² + (3√11)² = hypotenuse² → hypotenuse = 18

Note: 8² + 15² = hypotenuse² → hypotenuse = 17

Note: hypotenuse not needed for tan

Note: 2² + 6² = hypotenuse² → hypotenuse = 2√10
Answer:
Center: (-3,-2)
Radius: √6
The graph is attached.
Step-by-step explanation:
The equation of the circle has the form:

Where (h,k) is the point of the center of the circle and r is the radius of the circle.
The equation given in the problem is

Therefore:
h=-3
k=-2
The center is at (-3,-2)
And the radius is:

Then, you can graph it has you can see in the image attached.
(a) The rate that the point 8,28 represents is 3.5 cm/s since 28/8 = 3.5
(b) The unit rate is 3.5 cm/s since the rate is constant.
(c) The two points lie on the same line and that both points results to a rate of 3.5 cm/s.<span />