Making a factor tree is useful for us to see the factors of those numbers. Here we will take 12 and make a factor tree of it. Now we have to see those numbers with whom multiplication 12 comes. We will not take 1 and 12 here that is a obvious answer. We will take 3 and 4 there multiplication is 12. It will make the first branch of the tree now for the next branch we will take 3. 3 is a prime number 4 is not a prime number but multiplying 3*2*2 gives 12.