How many different triangles are there in the given equilateral triangle of length 5cm?

• 425
  15c3-(5c3+5c3+5c3)=425
• 11 years agoHelpfull: Yes(16) No(4)
• Answer 48.
  
  divide the 5cm triangle into 1cm equilateral triangles
  
  1cm triangles - 25
  2cm triangles - 13
  3cm triangles - 6
  4cm triangles - 3
  5cm triangles - 1
  
  so totally - 48 triangles.
• 11 years agoHelpfull: Yes(6) No(0)
• can u explain clearly @neetesh
• 11 years agoHelpfull: Yes(2) No(1)
• divide the sides of triangle into equal parts of 1cm each. to make a triangle we need 3 points. It can be either be 3 different points from 3 sides or it can be 2 points on one side and one point from the other
  writing the combinations we get..
  for 3 different sides:- 5c1*5c1*5c1= 125
  for 2 different sides: - 3c2*5c2*5c1*2= 1200
  
  so it should be 125+1200 triangles = 1325
  
• 11 years agoHelpfull: Yes(1) No(16)