FTCE Professional Education Practice Exam

How is the perimeter of a trapezoid calculated?

1. 1/2 h(a + b)

2. sum of lengths of sides

3. bh

4. 2(a + b)

The correct answer is: sum of lengths of sides

The perimeter of a trapezoid is calculated by finding the sum of the lengths of all its sides. A trapezoid has two parallel sides, often referred to as the bases, and two non-parallel sides. To determine the perimeter, you simply add the lengths of these four sides together. This means that if you have a trapezoid with side lengths labeled as a, b, c, and d, the formula would be: perimeter = a + b + c + d. This straightforward approach applies regardless of the trapezoid's dimensions or other properties, making it a reliable method for calculating perimeter in geometrical contexts. The other options provided reference different concepts: one deals with the area of a triangle, another calculates the area of a rectangle (bh), and one incorrectly suggests a formula that does not pertain to the perimeter of a trapezoid. Understanding the distinction between perimeter and area is key to applying the correct formula in geometric problems.