<h2>
Explanation:</h2>
In every rectangle, the two diagonals have the same length. If a quadrilateral's diagonals have the same length, that doesn't mean it has to be a rectangle, but if a parallelogram's diagonals have the same length, then it's definitely a rectangle.
So first of all, let's prove this is a parallelogram. The basic definition of a parallelogram is that it is a quadrilateral where both pairs of opposite sides are parallel.
So let's name the vertices as:

First pair of opposite sides:
<u>Slope:</u>

Second pair of opposite sides:
<u>Slope:</u>

So in fact this is a parallelogram. The other thing we need to prove is that the diagonals measure the same. Using distance formula:

So the diagonals measure the same, therefore this is a rectangle.
Answer:
C.
Step-by-step explanation:
Adding 2 fractions results in a fraction.
Probably is 64% I just think it’s is but I’m not sure
Answer:
x=4.63
Step-by-step explanation:
Area = (1/2) (base) (height)
20 = (1/2) (x+4) (x)
40 = x²+4x
x²+4x-40=0
Put in quadratic equation:
x=
x=
x=4.63324958071 or x=-8.63324958071
Since x can't be negative in this case we take our answer to be 4.63324958071, which rounds to 4.63