Final answer:
To calculate the area of the trapezoid, use the formula (1/2) * (b1 + b2) * h. With one side being 10 inches, its parallel side 20 inches, and the height 5 inches, the area is 75 square inches.
Step-by-step explanation:
To find the area of a trapezoid, we use the formula: A = (1/2) × (b1 + b2) × h, where b1 and b2 are the lengths of the parallel sides, and h is the height of the trapezoid.
According to the question, one side (b1) of the trapezoid is 10 inches. The side parallel to this (b2) is twice as long, so it is 20 inches. The height (h) is half as long as b1, therefore the height is 5 inches.
Now we plug these values into the formula:
A = (1/2) × (10 inches + 20 inches) × 5 inches
A = (1/2) × 30 inches × 5 inches
A = 15 inches × 5 inches
A = 75 square inches
Thus, the area of the trapezoid is 75 square inches.