The GCD of given numbers is 119.
Step 1 : Find prime factorization of each number.
$$\begin{aligned}357 =& 3\cdot7\cdot17\\[8pt]476 =& 2\cdot2\cdot7\cdot17\\[8pt]\end{aligned}$$(view steps on how to factor 357 and 476. )
Step 2 : Put a box around factors that are common for all numbers:
$$\begin{aligned}357 =& 3\cdot\color{blue}{\boxed{7}}\cdot\color{red}{\boxed{17}}\\[8pt]476 =& 2\cdot2\cdot\color{blue}{\boxed{7}}\cdot\color{red}{\boxed{17}}\\[8pt]\end{aligned}$$Step 3 : Multiply the boxed numbers together:
$$ GCD = 7\cdot17 = 119 $$This solution can be visualized using a Venn diagram.
The GCD equals the product of the numbers at the intersection.