The angles <3 and <6 are both examples of acute angles.
An acute angle is any angle that measures less than 90 degrees. In this case, both <3 and <6 are less than 90 degrees.
To understand what an acute angle looks like, you can imagine a slice of pizza. If you cut the pizza into 4 slices, each slice would form an acute angle. The tip of the slice would represent the vertex of the angle, and the two sides of the slice would form the rays that make up the angle.
So, in conclusion, both <3 and <6 are acute angles because they measure less than 90 degrees.