CONTEST : Find the total diagonal number of pentagon, quadrilateral and hexagon?

Many people have participated in the previous Math Contest. We are constantly announcing new contests to keep our community moving forward and we are giving the results of the contests in a timely manner. Anyway, today we are announcing another contest. Today's contest is also math related. We all probably know about the diagonal in geometry . A segment formed by the opposite vertices of a quadrilateral is called a diagonal. Our contest is about finding a diagonals . Hope everyone will like the contest and everyone will participate. The question is given in the picture below :

Translate the question into Bengali language : পঞ্চভুজ , চতুর্ভুজ এবং ষড়ভুজের মোট কর্ণের সংখ্যা বের করো ?
The rules and winner prizes for participating in the contest are described below :
* Rules for participating in the contest
- Find the answer and then Comment in the comment section in this post .
- Only one entry is allowed.
- The contest is open for the entire STEEMIT community.
- The first three people to comment on the correct answer will be considered first, second and third.
- Prizes will be shared among those who give correct answers after being first, second and third.
Total 10 Steem Prize Pool
| Rank | Prize |
|---|---|
| 1st | 3 Steem |
| 2nd | 2 Steem |
| 3rd | 1 Steem |
| 4th | the rest will be distributed over every correct answer |
Post Submission Deadline
This contest will Run for 3 Days that means Bangladesh time 10/04/2021, 11.59 pm (GMT+6) and Then the results will be announced.
So, participate soon and enjoy this contest.
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Zero-to-infinity
It's a bit tricky. But I had 16 diagonals
My ans And my entry
5 + 2 + 9 = 16
The ans is [ 16 ]
@zero-to-infinity @steemcurator01 @steemitblog
total number of diagonals is 16
I had 16 for the total number of diagonals
Total number is 16
My entry is 16
16 is my entry
16 diagonals
16
16