Riddles with transformations

Puzzles, riddles, brain teasers, conundrums, logic questions in pictures. There are questions here with various types of transformations of geometric images. In these logic tasks, puzzles and brain teasers, transformation is indicated by an arrow from left to right. To check your answer, click on the «Answer» button located below the task. After this, the correct answer and explanations will appear. Below you can select other questions on this topic. Typically each topic has 20 questions or more. At the same time, the complexity of logical problems gradually increases. First there will be easy questions, then medium, then difficult. Try to complete tasks as quickly as possible.
Question - 15
This difficult riddle-conundrum features two large geometric shapes on the left side and two small ones located inside the larger ones. To the right after the arrow is the final image. You must understand the logic of this transformation and choose the correct answer option, which should replace the question mark. You may need to apply unconventional thinking.
Correct answer = 5.
The number of angles in the two large geometric shapes minus the number of angles in the two small geometric shapes is equal to the number of angles in the geometric shape located to the right of the arrow. If, when subtracting angles, the sum is obtained with a minus sign, then the geometric figure on the right is painted in a dark color. This indicates that small geometric shapes have more angles than large geometric shapes.
-----------------------------------------------------------------------------------------------------------------------------