Calculate Trapezoid Area: Finding the Area of ABCD with Bases 6 and 8

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

• Step 1: Recall the formula for the area of a trapezoid.
• Step 2: Substitute the given values into the formula.
• Step 3: Calculate the area using arithmetic operations.

Let's work through each step:
Step 1: The formula for the area of a trapezoid is given by:
$\text{Area} = \frac{1}{2} \times (\text{Base}_1 + \text{Base}_2) \times \text{Height}$
Step 2: Plug in the values: $\text{Base}_1 = AB = 6$, $\text{Base}_2 = CD = 8$, and the height $AD = 3$.
$\text{Area} = \frac{1}{2} \times (6 + 8) \times 3$
Step 3: Perform the calculations:
$\text{Area} = \frac{1}{2} \times 14 \times 3 = \frac{1}{2} \times 42 = 21$

Therefore, the area of trapezoid $ABCD$ is $21$.