The GCD of given numbers is 45.
Step 1 :
Divide $ 180 $ by $ 135 $ and get the remainder
The remainder is positive ($ 45 > 0 $), so we will continue with division.
Step 2 :
Divide $ 135 $ by $ \color{blue}{ 45 } $ and get the remainder
The remainder is zero => GCD is the last divisor $ \color{blue}{ \boxed { 45 }} $.
We can summarize an algorithm into a following table.
180 | : | 135 | = | 1 | remainder ( 45 ) | ||
135 | : | 45 | = | 3 | remainder ( 0 ) | ||
GCD = 45 |
This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.