ABC is dilated by a scale factor of 3 with the origin as the center of dilation to form A'B'C'. The slope of AB is -1.2. The length of AB is p units, the length of AC is q units, and the length of BC is r units.

for this case we have by definition, if two lines are perpendicular, then the product of their slopes is -1.

then, given the following line:

so,

we are looking for m_ {2}:

then, the line is given by:

we find "b" replacing the given point:

finally, the equation is:

option c

the answer is 40.

proof: