Imagine reflecting triangle ABC across line MN. Then answer the questions about the reflected figure.

triangle

Step-by-step explanation:

Reflection of an figure across any line is the mirror image of the figure.

That means reflection of a figure is a rigid transformation, in which size or shape of the image doesn't change.

Therefore, when we reflect triangle ABC across the line MN shape of the reflected angle will remain same as a triangle.

for finding the midpoint of any given 2 pair of points simply add the respective x coordinates with other x coordinate and the y coordinate with other y coordinate and divide them by 2

in your question it will be :

(3+1)/2 for the x coordinate of mid point i.e 2

[8+(-4)]/2 for the y coordinate of midpoint i.e 2

so coordinates of mid point of points (3,8) and (1,-4) will be (2,2)

i hope this is what you were looking for.

see attached graph