Answer:
A(2,2)
Step-by-step explanation:
Let the vertex A has coordinates 
Vectors AB and AB' are perpendicular, then

Vectors AC and AC' are perpendicular, then

Now, solve the system of two equations:

Subtract these two equations:

Substitute it into the first equation:

Then

Rotation by 90° counterclockwise about A(2,2) gives image points B' and C' (see attached diagram)
Answer:
a) only extreme values are used in its calculation.
Step-by-step explanation:
In a data set, the range is given by the subtraction of it's highest value by it's lowest value.
The disadvantage is that it gives a high weight to extreme values, not focusing on central values. So the correct answer is given by option a