Mr. Unit Circle

The unit circle has coordinates at various points but the main coordinates are (1,0), (0,1), (-1,0), and (0,-1). (1,0) is zero in radians and (0,1) is pi/2 in radians and (-1,0) is pi in radians and (0,-1) is 3pi/2 in radians. (Cosine, sine) is cosine for x and sine for y. The first quadrant is positive for cosine and sine, the second quadrant is negative for cosine and positive for sine, the third quadrant is positive for cosine and negative for sine, and the fourth quadrant is positive for cosine and negative for sine. The unit circle is helpful for figuring out if a triangle is 45, 45, 90 triangle or 30, 60, 90 triangle. The unit circle is also the simplest way of finding lengths and angles of triangles. All sine, cosine, and tangent points have similar cordinates.