The GCD of given numbers is 29.
Step 1 : Find prime factorization of each number.
$$\begin{aligned}232 =& 2\cdot2\cdot2\cdot29\\[8pt]145 =& 5\cdot29\\[8pt]\end{aligned}$$(view steps on how to factor 232 and 145. )
Step 2 : Put a box around factors that are common for all numbers:
$$\begin{aligned}232 =& 2\cdot2\cdot2\cdot\color{blue}{\boxed{29}}\\[8pt]145 =& 5\cdot\color{blue}{\boxed{29}}\\[8pt]\end{aligned}$$Step 3 : Multiply the boxed numbers together:
$$ GCD = 29 $$This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.