find the no of non degenerate triangles whose vertices lie in the set of points (s,t) in the plane such that 0<=s<=4, s and t are integers

let O be the origin. Selec 2 different points from the set (0,0),(1,0),(2,0),(3,0) and (4,0)

this can be done in ⁵C₂ =10 ways

select one point from the set (0,1),(0,2),(0,3) and (0,4), this can be done in 4 ways

therefore, answer= 10*4 =40 triangles