Can we count the number of triangles in the figure with combination methods?

698 Views Asked by At

How many triangle can you find in following picture?

enter image description here

Solution: check picture solution,

enter image description here

But can we solve this problem with combination methods?

1

There are 1 best solutions below

1
On

$n$ lines emanating from a common point and crossing one or two other lines define $\binom n2$ triangles. You see such a configuration four times.