Answer:
78.5 ft²
Step-by-step explanation:
In this situation, the dog's 5 ft leash is the radius of the circle that he forms.
So, the radius is 5.
Use the area formula, A =
r². Plug in 5 as r, and 3.14 as 
A =
r²
A = (3.14)(5²)
A = (3.14)(25)
A = 78.5
So, the area of the grass he can cover is 78.5 ft²
10 , 20 , 30 , 40 , 50
8, 16 , 24, 32, 40
40 minutes
3. We can see that
1+100=101
2+99=101
3+98=101
.................
and so on
From 1 to 100, there are 50 pairs that has the sum is 101
Z=101×50=5050
4. We can see that
1-2=-1
3-4=-1
5-6=-1
...........
and so on
There are 10 pairs that has sum is -1
Z= 10×(-1)=-10