Explanation:
I can't draw here, but I can tell and explain to you what happens to the points (incl. N).
remember the slope of lines, and what happens when we have to create a perpendicular slope (90°) ?
x and y in the slope ratio y/x go upside down and the sign flips (that means it flips for one of them).
a rotation by 90° follows the same principles.
x and y trade places, and for one of them the sign flips.
the only "difficult" trick is to determine, if the sign of x or of y flips.
let's look at N first.
N = (-5, -4)
the rotation counterclockwise takes it over into the 4th (bottom right) quadrant, where x values are positive.
aha, so the sign of x flips after x and y trade places, and we get
N' = (4, -5)
now for the other points
X = (-3, -2)
the same principle as for N
X' = (2, -3)
B = (-4, 1)
this is now moving from the 2nd (where y values are positive) to the 3rd quadrant (where x and y are negative).
so, again the sign of x flips after x and y trade places
B' = (-1, -4)
with the new coordinates of the points you can now easily draw the new triangle'.