Find the corresponding point on the unit circle for the radian measure given below. 0=9pi/2

We have that

step 1
convert to degrees
∅=9pi/2> convert  to degrees> 9*180/2> 810°
810°/360°> 2.25
0.25*360> 90°
∅=90°> belong to the I quadrant

step 2
find the x-y coordinates in the unit circle
r=1 unit
x=r*cos ∅> 1*cos 90> x=0
y=r*sin ∅> 1*sin 90°> y=1

the answer is
the point is (0,1)

Horizontal change or the change of x

The answer is 41.7 because 1.39 times 30 is 41.7