The GCD of given numbers is 23.
Step 1 : Find prime factorization of each number.
$$\begin{aligned}23 =& 23\\[8pt]46 =& 2\cdot23\\[8pt]\end{aligned}$$(view steps on how to factor 23 and 46. )
Step 2 : Put a box around factors that are common for all numbers:
$$\begin{aligned}23 =& \color{blue}{\boxed{23}}\\[8pt]46 =& 2\cdot\color{blue}{\boxed{23}}\\[8pt]\end{aligned}$$Step 3 : Multiply the boxed numbers together:
$$ GCD = 23 $$This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.