Answer:
C. 90°
Step-by-step explanation:
To map point A to B from the middle of the square say we are using a compass from a mathematical set
Now from the point A of the square place the needle point of compass and strike an arc in the square using an arbitrary adjustment of the compass
With same adjustment place the needle side of the compass at point B and strike another arc to bisect the first arc,
Let say this third point is O
using a ruler and a pencil join the three points.
By inspection Points A and B are now 45° each. This is because sum of angles in a square is 90° and we just bisected A and B into two
From inspection also
ABO is a triangle
If A and B are 45°each then O is 90°
This is because sum of angles in a triangle is 180 °
45+45+90=180°
Hence the angle of rotation about the center that maps A and B is 90°
