<h1>Do you like"missing number"?</h1>

Here one more brain teaser missing number from the collection
Brain teasers and puzzles "Missing number practice" 
by Panos kalliantasis

Another missing number to apply and improve your ability to answer such questions in competitive exams.

 

 The secret to these math puzzles is to find the relation that holds true and is the same for the figures.
 
 For more practice to missing numbers questions brain teasers puzzles

 Below you will find the answers and solutions, try many of them yourself before you see the solutions.

 

 

Answer

 The missing number is 21