A community for students.
Here's the question you clicked on:
 0 viewing
 2 years ago
9 dots are drawn as below. How many triangles can be formed by joining three dots?
 2 years ago
9 dots are drawn as below. How many triangles can be formed by joining three dots?

This Question is Closed

virtus
 2 years ago
Best ResponseYou've already chosen the best response.1@UnkleRhaukus hope your not here to troll me again

UnkleRhaukus
 2 years ago
Best ResponseYou've already chosen the best response.0thats not my style @virtus

UnkleRhaukus
 2 years ago
Best ResponseYou've already chosen the best response.0i can see four 2x2 triangles

UnkleRhaukus
 2 years ago
Best ResponseYou've already chosen the best response.0i suppose the dont have to be right angles

ash2326
 2 years ago
Best ResponseYou've already chosen the best response.0@virtus do you have options?

virtus
 2 years ago
Best ResponseYou've already chosen the best response.1not sure what you mean by options @ash2326 but incase you were wondering, my solution book says 9C3 8

virtus
 2 years ago
Best ResponseYou've already chosen the best response.1@UnkleRhaukus you have PARTIALLY redeemed yourself

UnkleRhaukus
 2 years ago
Best ResponseYou've already chosen the best response.0i feel better already,

virtus
 2 years ago
Best ResponseYou've already chosen the best response.1good to know, why don't you change feeling "good" to "euphoric" by suggesting why the answer is 9C3 8

UnkleRhaukus
 2 years ago
Best ResponseYou've already chosen the best response.0say you want to find all the triangle that have the top left as a vertex, how many can you make

mukushla
 2 years ago
Best ResponseYou've already chosen the best response.19C3 triples which are in the same line=9C38 dw:1342275604359:dw

UnkleRhaukus
 2 years ago
Best ResponseYou've already chosen the best response.0i count eighteen dw:1342275638118:dw

UnkleRhaukus
 2 years ago
Best ResponseYou've already chosen the best response.019,20dw:1342275746454:dw

virtus
 2 years ago
Best ResponseYou've already chosen the best response.1but hows that joining three dots?

UnkleRhaukus
 2 years ago
Best ResponseYou've already chosen the best response.0mukushla is right , we are misusing the straight lines because they are not triangles

mukushla
 2 years ago
Best ResponseYou've already chosen the best response.1different triangles can be formed by joining 3 of the dotes unless 3 dots are in the same line, so C(3,9)8

virtus
 2 years ago
Best ResponseYou've already chosen the best response.1but why is do we minus 8

mukushla
 2 years ago
Best ResponseYou've already chosen the best response.1u can count triples of dots that are in the same line just like what i did up there

UnkleRhaukus
 2 years ago
Best ResponseYou've already chosen the best response.0this is not a triangle dw:1342276198984:dw
Ask your own question
Sign UpFind more explanations on OpenStudy
Your question is ready. Sign up for free to start getting answers.
spraguer
(Moderator)
5
→ View Detailed Profile
is replying to Can someone tell me what button the professor is hitting...
23
 Teamwork 19 Teammate
 Problem Solving 19 Hero
 Engagement 19 Mad Hatter
 You have blocked this person.
 ✔ You're a fan Checking fan status...
Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.