C= 2*pi*r
pi= approx. 3.14
So
The first one with the radius being 18 would be approximately 113.04
BECAUSE 18 * 2 = 36
36*3.14= 113.04
DO THE SAME PROCESS with the other values you were given...
Also if they give you the diameter the formula is C= d*pi
that formula is the same as c=2*pi*r ..... Use either... just remember when they give you the radius.... the radius is half of the diameter... so take the radius times 2 and times that by pi
When it asked for an approximation use 3.14 for pi.
I'm sure you can do the rest by yourself. I hope this helped!
Answer: 
Step-by-step explanation:
The area of a rectangle can be calculated with the formula:

l: the length of the rectangle.
w: the width of the rectangle.
The area of the remaning wall after the mural has been painted, will be the difference of the area of the wall and the area of the mural.
Knowing that the dimensions of the wall are
by
, its area is:

As they are planning that the dimensions of the mural be
by
, its area is:

Then the area of the remaining wall after the mural has been painted is:

Answer:
y=75° (opposite angle of parallelogramare equal)
x+8=16(opposite sides are equal)
x=16-8
x=8
In order to solve this we can first convert 3h 28m to 208 minutes.
This will make it so we can find how many minutes it took her to run per mile.
The way we do that is by dividing 208 by 26. This leaves us with 8 minutes per mile.
Hope this helped at least a bit!
<3