Hey what is Apr? So I can help you with this; )
Answer:
120960
Step-by-step explanation:
Given that a librarian has a set of ten different books, including four different books about Abraham Lincoln.
The librarian wants to put the ten books on a shelf with the four Lincoln books next to each other, somewhere on the shelf among the other six different books.
First arrnage the 6 other books in the shelf.
This can be done in 
Now arrange the 4 books of Lincoln
This can be done in 
Now we have 7 places to insert Lincoln books including two corners and in between.
Thus this can be done in 7 ways
Total no of ways = 
Answer: The area is approximately 314 ft^2
Step-by-step explanation:
Well if the diameter is 20 feet then the radius will be 10 because the radius is half the diameter, and to find the area of a circle, you use the formula
A=
where A is the area and pi times the radius squared.
We will represent pi by 3.14
A= 3.14* 10^2
A= 3.14 * 100
A = 314

I only know this because I remember the common fractions, and 1/3 is .3333 repeating.
False because there are no parrelell lines