Answer:

Step-by-step explanation:
The reference angle is an acute angle that angle in standard position makes with the positive x-axis.
The given angle in radians is

This angle is already acute and hence it is itself a reference angle.
The reference angle of any angle in the first quadrant is the same angle.
Answer:
ABD = CDB
AB is parallel to DC
Step-by-step explanation:
angle a and c are right angles so they are equal and angle b and d are equal because they have a line that touch both letters
AB and DC are parellel because they are the same looking lines just on oppisite sides
first you have to find the triangle, then you can move to the actual question.
x+30+80 = 180
x+110 = 180
x+110 - 110 = 180-110
x =70
now you can go to the actual question.
y + 70 = 180
y+70- 70 = 180-70
y = 110
there is your answer. hope this is helpful