Identify parameters

Identify the lengths of the parallel sides as $a = 12$ and $b = 18$, and the height (distance between sides) as $h = 10$.

$a=12, b=18, h=10$

Apply Area formula

The formula for the area of a trapezium is half the sum of parallel sides multiplied by the height.

$\text{Area} = \frac{1}{2} \times (12 + 18) \times 10$

Perform calculation

Add the parallel sides to get $12 + 18 = 30$, then multiply by the height $10$ and divide by $2$.

$\text{Area} = \frac{1}{2} \times 30 \times 10 = 15 \times 10 = 150$