Answer:
90
Step-by-step explanation:
Answer: use photo math if u are virtually
Step-by-step explanation:
Answer:
The coordinates of the fourth vertex of the rectangle is 
Step-by-step explanation:
Let

using a graphing tool
Plot the vertices of the rectangle
The coordinates of point D will be the intersection point of the line parallel to AC that passes through the point B with the line parallel to AB that passes through the point C
The intersection point is 
see the attached figure
250
100 + 200 + 300 + 400 = 1000
1000/4 = 250