Explanation: 1- Slope of DE: Assume point D is (x1, y1) and point E is (x2, y2). To get the slope of DE, we will substitute with the given points in the following formula: slope of DE = (y2-y1) / (x2-x1) = -2
1- Slope of AC: Assume point A is (x1, y1) and point C is (x2, y2). To get the slope of AC, we will substitute with the given points in the following formula: slope of AC = (y2-y1) / (x2-x1) = -2
3- Therefore, the easiest way to get the slope of any line is by using the slope formula.
4- Note that since the two slopes are equal, this means that the two lines are parallel.