A= 2 to the power of -1
Because if it's the same base no in multiplication we add the indices and in division we subtract the indicies
Slope = (8 -2) / (1 + 5) =6/6 = 1
Parallel lines, slope is the same
So the slope of any line parallel to the line containing (-5,2) & (1,8) is also equal 1
Answer:

Step-by-step explanation:
In order to find the area of a circle we multiply π by the radius, and to find the radius of a circle we have to look at the line that stops directly in the middle of the circle.

Once we then have the radius, we simply multiply the radius, (with an exponent of 2) by π and then we will have our answer. Of course, round if needed.

Hope this helps.

so the slope of that line above is really -4/3, now

interior angle of a regular 18-gon.
It is easier to calculate the exterior angle of a regular polygon of n-sides (n-gon) by the relation
exterior angle = 360/n
For a 18-gon, n=18, so exterior angle = 360/18=20 °
The value of each interior angle is therefore the supplement, or
Interior angle = 180-20=160 degrees.
Naming of a 9-gon
A polygon with 9 vertices is called a nonagon (in English) or enneagon (French ennéagone, but the English version is sometimes used)
You had a good start with the correct answer.
Exterior angle of a 15-gon
The exterior angle of a 15-gon can be calculated using the relation given in the first paragraph, namely
Exterior angle = 360/15=24 degrees