The GCD of given numbers is 6.
Step 1 :
Divide $ 42 $ by $ 36 $ and get the remainder
The remainder is positive ($ 6 > 0 $), so we will continue with division.
Step 2 :
Divide $ 36 $ by $ \color{blue}{ 6 } $ and get the remainder
The remainder is zero => GCD is the last divisor $ \color{blue}{ \boxed { 6 }} $.
We can summarize an algorithm into a following table.
42 | : | 36 | = | 1 | remainder ( 6 ) | ||
36 | : | 6 | = | 6 | remainder ( 0 ) | ||
GCD = 6 |
This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.