1.34 radians is around 77^circ, comfortably in the first quadrant.
theta = 1.34 is thus a ray from the origin into the first quadrant. It's not the line through the angle, because the part of the line in the third quadrant satisfies theta = 1.34 + pi.
So, understanding x>0, y>0 we take tangents and get
tan theta = tan(1.34)
Since
x = r cos theta
y = r sin theta
we get
tan theta = y/x
and our equation becomes
y/x = tan(1.34)
y = x tan(1.34) quad for x > 0.
That's the ray through the origin and the first quadrant with slope tan(1.34). We explicitly exclude x=0 which doesn't have the required angle.
