Calculate Trapezoid Perimeter: Finding the Sum of Sides 9, 12, 5, and 4

To solve this problem, we'll follow these steps:

• Step 1: Identify the given side lengths of the trapezoid.
• Step 2: Use the perimeter formula for a trapezoid, which is the sum of the lengths of its sides.
• Step 3: Perform the necessary addition to compute the perimeter.

Now, let's work through each step:
Step 1: The trapezoid has side lengths of $9$, $5$, $12$, and $4$.
Step 2: The formula for the perimeter $P$ of a trapezoid is:
$P = \text{side}_1 + \text{side}_2 + \text{side}_3 + \text{side}_4$
Step 3: Plugging in the values, we compute:
$P = 9 + 5 + 12 + 4$
Step 4: Calculating the sum:
$P = 30$

Therefore, the perimeter of the trapezoid is $30$.