Convert to Y=MX+B to make it easier, minus 2x from both sides to get -7y=-2x+14, then divide it all by -7 to get y=2/7x-2. 2 equals your starting point, from there go down 2 and over 7 for you slope and repeat until the graph is done.
Answer:
the answer is DBC=90°
because the midpoint of the perimeter of quadrilateral is B
1 is not. 2 is. 3 is not. 4 is. 5 is. 6 is. 7 is not. 8 is.