When to use chain rule and product rule?

how do i differentiate between these two. very

Chain rule when it's one function inside another.

d/dx f(g(x)) = f’(g(x))*g’(x)

Product rule when two functions are multiplied side by side.

d/dx f(x)g(x) = f’(x)g(x) + f(x)g’(x)

step-by-step explanation:

∆abc has the points a(1, 7), b(-2, 2), and c(4, 2) as its vertices. formed with the point d(1, 2) as its third vertex, then ∆abd is triangle.