1. You got it right.
4π/9 x 180/π = 80°
2. To get a coterminal angle you start with your angle and then you add or subtract 360° (one cycle around the circle).
-123+360+360 = 597°
-123-360 = -483°
3. The angle is 215° from the point (1,0) on the unit circle. The angle 215° is between 180° and 270° so it is in quadrant 3.
Lets take it in order:
1) 90 deg because the angle right next to it is a right angle
2) 128 deg becasue of the angle directly across from it
3) x = 180 - 128 = 52 deg
4) 180 = 90 + 52 + x so x = 180 - 90 - 52 = 38
5) 180 = 38 + x so x = 180 - 38 = 142
6) Same as 4
7) Same as 5
Check my math, as I just did it in my head
Her salary 4 years ago would have been $30,000.
If 45,000 is 15,000 less than double her previous salary, we must first add 15,000 to 45,000 to find what double her salary was.
45,000+15,000=60,000.
Since this is twice her salary, we divide this by 2.
60,000/2= 30,000.
So, her salary 4 years ago would have been $30,000.
I hope this helps!
36 miles an hour
3miles/5min to x/60min multiply top and bottom by 12 and you get 36miles/60min
