Answer:

Explanation:
First, to find the original line, employ the slope formula.

The slope of your original line is
.
Next, plug in your slope and the third point to the point-slope formula.

To find the line which is perpendicular to the line, take the opposite reciprocal of the slope.
To find the opposite, flip the sign.
is negative, so it will become
, which is positive.
To find the reciprocal, flip the fraction.
would become
.
Your slope for the perpendicular line is
, so your line is:
