There are three interior angles, all of which can be found.
First, the length of the sides. CA=5, because we can use Pythagoras and the coordinates and of points A and C:
AC^2=(2-(-1))^2+(3-(-1))^2=9+16, so AC=sqrt(25)=5.
Similarly, BC=sqrt(61) and AB=sqrt(10), using the coords of B and C, and A and B.
Using the cosine rule, we can find angle A:
a^2=b^2+c^2-2bccosA:
61=25+10-2*5sqrt(10)cosA; cosA=-26/(10sqrt(10))=-0.8222, A=145.30 degrees.
We can now use the sine rule to find angle B:
sinB/b=sinA/a:
sinB=5*0.5692/sqrt(61)=0.3644, B=21.37 degrees. Angle C=180-(A+B)=13.33 degrees.