Lydia graphed ΔDEF at the coordinates D (−2, −1), E (−2, 2), and F (0, 0). She thinks ΔDEF is a right triangle. Is Lydia's assertion correct? Yes; the slopes of segment EF and segment DF are opposite reciprocals.
Yes; the slopes of segment EF and segment DF are the same.
No; the slopes of segment EF and segment DF are not opposite reciprocals.
No; the slopes of segment EF. and segment DF are not the same.

No; the slopes of segment EF and segment DF are not opposite reciprocals.

Step-by-step explanation:

The slope between two points O(e, f) and X (g,h) is given as:

The slopes of segment EF and segment DF are given below:

For triangle DEF to be a right triangle, DF and EF are supposed to be perpendicular to each other. Two line are said to be perpendicular if the product of their slope is -1, i.e the slope of one line is the negative reciprocal (opposite reciprocal) of the other line.

Since the slope of DF and EF are not opposite reciprocals,  ΔDEF is not a right triangle.

this may not be at all, but i use the same website you're using for school, and if i'm stuck doing one of these i try to look for it on the section.