Area of a Trapezoid
📐 What is a Trapezoid?
A trapezoid (also called a trapezium in some countries) is a quadrilateral with exactly one pair of parallel sides.
Key Vocabulary:
- Bases ($b_1$ and $b_2$): The two parallel sides
- Legs: The two non-parallel sides
- Height ($h$): The perpendicular distance between the two bases
- Midsegment (Median): A segment connecting the midpoints of the legs, with length $\frac{b_1 + b_2}{2}$
Interactive visualization — available in the full lesson
🔑 The Formula
$$A = \frac{1}{2}(b_1 + b_2) \times h$$
Where:
- $A$ = area of the trapezoid
- $b_1$ = length of the first base (one parallel side)
- $b_2$ = length of the second base (other parallel side)
- $h$ = height (perpendicular distance between the bases)