It would be 40.
60 minus 20 = 40
Difference means subtraction
ANSWER

EXPLANATION
The outermost square tile has side length,

The area of a square is given by;

We substitite the given expression for the side length into the formula to obtain,


We expand using the distributive property to obtain;

This gives us:


The last choice is correct.
Answer:
My sister will swing the total distance = 40 feet
Step-by-step explanation:
On the first swing my sister travels a distance of 8 feet.
In every successive swing she travels 80% of the distance of the previous distance.
So the sequence formed by the distance traveled in every swing will be a geometric sequence.
First term of the sequence 'a' = 8 feet
common ratio 'r' = 0.80
Since this sequence is an infinite geometric sequence,
Sum of this sequence =
[Since r < 1]
= 
=
= 40 feet
Therefore, my sister will cover the total distance = 40 feet
1.
In any trapezoid, the length of the midsegment is

substituting the known values:



2.
Notice that since D and have the same y-coordinate, then DE is horizontal, and since F and D have the same x-coordinate, FD is vertical.
Thus FD and DE are perpendicular, so the triangle FED is a right triangle.
The median drawn from the right angle, is equal to half the hypotenuse.
That is, |DO|=1/2 |FE|, thus |OE|=|OF|=|OD|, are all radii of the circle centered at O.
O is the midpoint of EF, and is found by the Midpoint formula:

Answer:
1. 14
2. (4, 3)