The problems with extra information, are difficult to solve because sometimes, not all data should be used.
Therefore, students begin to doubt the fact that they are not using all the information raised in the problem.
Example:
Problem:
Suppose we have a triangle with a right angle. The problem gives us as data an angle and the sides of the triangle. We want to determine the length of the hypotenuse.
Solution:
Using the Pythagorean theorem we can solve the problem.
The given angle data is an extra information that you should not use for this case.