A problem on triangles mostly geometry type.i had one in which 87 lines were given like a truss.First 3 formed a triangle and from next onwards every 2 formed a triangle.We had to find total number of triangles.

• 43
  first 3 lines form a triangle so
  87-3=84
  next 2 lines form a triangle so no of triangle=84/2
  42
  42+1=43
• 11 years agoHelpfull: Yes(37) No(0)
• 1st traingle-3 lines
  next no. of traingle
  left lines-84
  every 2 lines form a traingle-
  84c2
  total traingle- 84c2+1
• 11 years agoHelpfull: Yes(5) No(8)
• 1st triangle+ 84/2= 43 traingle
  
• 11 years agoHelpfull: Yes(2) No(1)
• 43 should be the ans
• 11 years agoHelpfull: Yes(2) No(0)
• 43+1=44 triangles.... already we have taken one triangle know in which three lines form 1 triangle 87-3=84 then 84/2=42 so 42+1(formed by three lines)+1(given)= 44
  
• 11 years agoHelpfull: Yes(2) No(5)