2. x y 0 radians 2  radians  radians radians radius = 1 unit(1,0) (0,1) (-1,0) (0,-1) (1,0)

3. 0 22 x y  radians 45  x 1 y x 2 + y 2 = 1 2 In a 90-45-45 triangle x = y therefore: x 2 + x 2 = 1 2 2x 2 = 1 x 2 = x = x = y = In Quadrant I both x and y are positive.

4. radians 0 In Quadrant II x is negative and y is positive. In Quadrant III x is negative and y is negative. In Quadrant IV x is positive and y is negative. (+,+)(-,+) (-,-)(+,-) By dividing each quadrant in half, four more points around the 2  radians making one circle are identified. The 2  has been divided into eight equal parts. 2   8 =

5. 60  0 y The 3 red lines divide the circle (2  ) into 6 equal parts. 2   6 = 60  1 In a 90-60-30 right triangle the side opposite the 30  angle is one-half the hypotenuse. 1 y ( ) 2 + y 2 = 1 2 + y 2 = 1 y 2 = 1 - y 2 = y = =

6. x y 0 (+,+)(-,+) (-,-)(+,-) This family of points have identical order pairs except that the signs change according to the Quadrant occupied by the point.

7. 2   12 = Of all of the angles discussed thus far only 4 of them are not in the diagram shown above. By using the lines from the last family and new blue intersecting lines, the circle is divided into 12 congruent angles.

8. 30° 1 In a 90-60-30 right triangle the side opposite the 30  angle is one-half the hypotenuse. x 2 + ( ) 2 = 1 2 x 2 + = 1 x 2 = 1 - x 2 = x = = x (+,+)(-,+) (-,-)(+,-) 30° 1

9. 0 22  (1,0) (0,1) (-1,0) (0,-1) (1,0)