the angle created by a radius along the circumference of a circle.
To convert from radians to degrees: multiply by 180/ㅠ
To convert from degrees to radians: multiply by ㅠ/180
It's radian, so you multiply 180/ㅠ = 282.9 degrees
If you convert degrees to radians, then you leave ㅠ(pie) in answer
I can't put any images on here, because it doesn't work for me.
But, if you want to see completed Unit circle, go to
Based on 30-60-80 traingle and 45-45-90 tirangle,
you can find out the cosine and the sine of angle of unit circle.
30' has cosine of square root 3 over 2
You can get this by knowing 30-60-90 triangle
cosine is adj/hyp.
SO! it is squre root 3 over 2.
sine of 30' is 1/2.
sine is opp/hyp
So! it is 1/2
It's same way with 45-45-90 triangle.
In Unit circle,
1 & 2 quadrants is sine POSITIVE.
2& 3 quadrants is cosine NEGATIVE.
you have to becareful of this