How many triangles are there in the following figure?

28 24 14 20

28

Let's add all the number of triangles to find out the total number of triangles; 01+02+03+04+05+06+07= 28 total number of triangles in the given figure. Or, We can use the formula of "Sum of natural numbers" which is; n(n+1)/2 Therefore, 7(7+1)/2 =  \(\frac{56}{2}\)= 28 number of triangles.