PLEASE EXPLAIN THIS! :(
At the end of a meeting all participants shook hands with each other. 28 handshakes were exchanged. How many people were in the meeting?

Question

PLEASE EXPLAIN THIS! :( 
At the end of a meeting all participants shook hands with each other. 28 handshakes were exchanged. How many people were in the meeting?

anonymous · Answer

if there was one person there'd b no handshakes, if there were 2 there'd be 2, if there were 3 there'd x be so it follows a pattern similar to (n+1) write the formula and find the solution

anonymous · Answer

if there were 2 there'd be 1*

anonymous · Answer

I didn't get it. :(

anonymous · Answer

Also writing a picture could be helpful in finding the formula|dw:1376509169097:dw|