The GCD of given numbers is 5.
Step 1 : Find prime factorization of each number.
$$\begin{aligned}235 =& 5\cdot47\\[8pt]95 =& 5\cdot19\\[8pt]145 =& 5\cdot29\\[8pt]\end{aligned}$$(view steps on how to factor 235, 95 and 145. )
Step 2 : Put a box around factors that are common for all numbers:
$$\begin{aligned}235 =& \color{blue}{\boxed{5}}\cdot47\\[8pt]95 =& \color{blue}{\boxed{5}}\cdot19\\[8pt]145 =& \color{blue}{\boxed{5}}\cdot29\\[8pt]\end{aligned}$$Step 3 : Multiply the boxed numbers together:
$$ GCD = 5 $$This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.