How Many Triangles Can You See In The Figure Below?

by

Time for a quick geometry lesson.

Count the number of triangles in the picture below;

How Many Triangles Can You See In The Figure

So were you able to solve the riddle? Leave your answers in the comment section below.

If you get the correct answer, please share it with your friends and family on WhatsApp, Facebook and other social networking sites.

[showhide more_text=”Show Answer” less_text=”Hide Answer”]

Answer: 36.

Polygon (Pantagon)
ABC, ACD, ADE, BCD, BDE,BEA, CDE, CEA,DAB, EBC = No. of triangles = n = 10
AB, BC, CD, DE, AE = No of sides = r = 5
Total Number of Triangles =?
We use combination method: 10c5 = 10!/5!(10-5)!=10!/5!5!=(10.9.8.7.6.5.4.3.2.1)/(5.4.3.2.1.5.4.3.2.1)=36

Note: nCr = n!/r!(n-r)!
Answer contributed by: Dr. Nadeem Hussain Qureshi (dnhq1970@gmail.com)

[/showhide]

7 thoughts on “How Many Triangles Can You See In The Figure Below?”

  4. Polygon (Pantagon)
    ABC, ACD, ADE, BCD, BDE,BEA, CDE, CEA,DAB, EBC = No. of triangles = n = 10
    AB, BC, CD, DE, AE = No of sides = r = 5
    Total Number of Triangles =?
    We use combination method: 10c5 = 10!/5!(10-5)!=10!/5!5!=(10.9.8.7.6.5.4.3.2.1)/(5.4.3.2.1.5.4.3.2.1)=36

    Note: nCr = n!/r!(n-r)!
    Dr. Nadeem Hussain Qureshi (dnhq1970@gmail.com)

    Reply

Leave a Comment