Number of Triangle

---

Soln.

1+2+3+4 = 10

1+2+3 = 6

1+2 = 3

Total Triangle = 10+6+3 = 19

Soln.

Number of Triangle from Bottom Line = 1+2+3+4 = 10 , count total bottom line. Here 3 bottom line.

= 10 x 3 

= 30