If you knew how to use a graph, this problem would be very easy. I suggest you learn quick, because graphing problems will turn up all throughout your future mathematics classes… especially in the higher levels.

If you don’t know what perpendicular means, see the source link.

The negative reciprocal for 2 is -1/2. (It’s one over the original number, multiplied by -1).

Find the slope between the two points for the one side and then find the slope between the two points that define the other side, using the slope formula. If the two slopes are negative reciprocals, then the sides are perpendicular. If the slopes are not negative reciprocals, then the sides are not perpendicular.

slope is (y2-y1) / (x2-x1)

so the first slope would be 1/3

the second slope would be -3

so if we multiply 1/3 times -3 you get -1

so yeah it is perpendicular