The rule for clockwise rotation of 90 degrees about the origin is (-y, x).
So (-1,9) would now be (-9,1).
Hope this Helps!!
6/2 is the number 6 being divided in half by 2; to figure this out just count your 2 table factors! Shown work:
2 x 2 = 4
2 x 3 = 6!
So 6 divided by 2 (6/2) is just the oppoposite of 2 x 3 = 6
or 
divide both sides by 2
sinΘ = - 
Since the sin ratio is negative then Θ is in third / fourth quadrants
Θ = 
() = 
related acute angle
Θ = ( π + ) =
or Θ = ( 2π - ) =
The point (2, -5) would not be one of the correct vertices of the reflected shape.
When we reflected a shape across the line y=x, we just replace the x's with y's and y's with x's.
Our new points are (5, 2) (4, 6) and (3, 3). None of the points contain negative numbers.
