Which equation can be used to determine the reference angle, r, if theta=7pi/12?

r = 180° -

Step-by-step explanation:

We have to find the reference angle (r) of the given angle θ =

First we will find the quadrant in which this angle lies.

Since θ = =

105° angle lies in second quadrant. Therefore, reference angle will be

r = 180° - θ

where θ =

Now we can say that equation for reference angle r will be r = 180°-

i need the table so i can see

step-by-step explanation:

a 4/6 = 9/12   not proportional

step-by-step explanation:

to find which are not proportional, we can use cross products

if it is true, they are proportional.   if it is not true, they are not proportional.

a 4/6 = 9/12

4* 12 = 6*9

48 = 54

not this is not proportional  

b 2/3 = 12/18  

2* 18 = 3 * 12

36 = 36

this is proportional

c 5/4 = 10/8  

5*8 = 4*10

40 = 40

this is proportional

d 7/5 = 35/25

7*25 = 5 * 35

175 = 175

is proportional