Answer:5) c= 25.12 cm
6) c= 282.6 m
7) c= 13.188 mi
8) c= 6.28 cm
Step-by-step explanation:
C= 2 x pi x r
Circumference = 2 x 3.14 x radius ( radius is half the diameter of the circle)
Correct Answer: 
We are to find:

Multiplying and simplifying the radicals, we get:
C is the correct answer because triangles always equal to 180 degrees
If it doesn't matter whether the points are integers or not you can just pick a number for either y or x and solve for the other variable. For example, if you pick 3 to be your x, plug it in and then solve for y. Start out with:

Plug in 3 for x:

. Then,

. Subtract 21 from both sides and then divide by -3 on both sides. You end up with y=-7 so one of your points is (3, -7)