Question

What coordinate for F would make triangle ABC and triangle DEF congruent? (The file of the image is attached!)

Answer 1

(-2,-3) would make these two triangles congruent.

If you look at the slope of line DE, you see it has a -1 slope.
Line BA also has a -1 slope.
So line AC = line FE and line BC = line FD

The slope of AC is 3
The slope of BC is 1/3
Two possible points for F are (2,1) and (-2,-3)
Since (2,1) is not an option, C. (-2,-3) is your answer.

Answer 2

(-2,-3) The x and y coordinates are the opposites of the original shape's coordinates.

Ex) Point B matches up with Point E. Point B coordinates are (-1,2). And Point E coordinates are (1,-2). opposite of -1 is 1 and opposite of 2 is -2.