The angles number would be 230
The coordinates (abscissa and ordinates) of the midpoint of the line segment is the average of the abscissas and the ordinates, respectively. Therefore, the x - coordinate of the midpoint is equal to -20 + 20 or 0 by 2 which is zero. The answer is letter E.
Answer:

Step-by-step explanation:
we know that
The sides of a rhombus are all congruent and the diagonals are perpendicular bisectors of each other
so
Applying the Pythagorean Theorem

where
c is the length side of the rhombus
a and b are the semi-diagonals
we have

substitute the values



To find out the perimeter of the rhombus multiply the length side by 4


Look at picture for details