Answer: 90 clockwise
Explanation:
To explain whats happening you need to first identify the points on the graph.
Here in the image your points are:
A (1,3)
B (6,6)
C (5,0)
Then with the rotation of the points you have the following new points:
A' (3,-1)
B' (6,-6)
C' (0,-5)
If you look closely at the way the points are moving the x and y switched places, the y stayed positive while the x became negative, hence making this a 90 degree clockwise rotation.
Here I will attach an image of a chart that explains what the answer will be based on the points for further help on future questions!