Trapezoid Area Table: Area by Parallel side a
Reference table of area for Trapezoid Area across a range of parallel side a values — exact, engine-computed figures you can read off at a glance.
Trapezoid Area Calculator
Verified formula Updated Jun 2026 Private — runs on your device
Verified formula
Private
Area
30.0000
- Median (mid-segment)
- 6.0000
For general information only — not financial, tax, legal or medical advice. Verify before you rely on it.
How to use the Trapezoid Area Calculator
The Trapezoid Area Calculator works out your area, along with 1 related figure in an instant. Enter parallel side a, parallel side b and height (perpendicular) and the result updates as you type — it is free, needs no sign-up, and runs entirely in your browser so your figures stay private.
- Enter the parallel side a.
- Enter the parallel side b.
- Enter the height (perpendicular).
- Read off your area, together with median (mid-segment) — the calculator updates automatically, with no button to press.
Formula
The Trapezoid Area Calculator uses the formula:
Area = (Parallel side a + Parallel side b) ÷ 2 × Height (perpendicular)
Worked example
For example, with parallel side a of 8 units, parallel side b of 4 units and height (perpendicular) of 5 units, the area is 30.0000.
| Parallel side a | 8 units |
|---|---|
| Parallel side b | 4 units |
| Height (perpendicular) | 5 units |
| Area | 30.0000 |
|---|---|
| Median (mid-segment) | 6.0000 |
Results are estimates for educational use, not professional advice.
Key terms explained
- Median
- The middle value of a sorted set of numbers, less affected by outliers than the mean.
- Area
- The amount of two-dimensional space a shape covers, measured in square units.
Frequently asked questions
Average the two parallel sides and multiply by the height: A = ½(a + b)h. With parallel sides 8 and 4 and height 5, the area is ½ × 12 × 5 = 30 square units.
It is the perpendicular distance between the two parallel sides, not the length of a slanted side.
The median, or mid-segment, is the average of the two parallel sides. It equals the length of a line halfway between them.
The shape with one pair of parallel sides is called a trapezoid in US English and a trapezium in British English. The area formula is the same.
The Trapezoid Area Calculator uses the formula: Area = (Parallel side a + Parallel side b) ÷ 2 × Height (perpendicular). For example, with parallel side a of 8 units, parallel side b of 4 units and height (perpendicular) of 5 units, the area is 30.0000.
Enter the parallel side a. Enter the parallel side b. Enter the height (perpendicular). Read off your area, together with median (mid-segment) — the calculator updates automatically, with no button to press.
Related guides
How to Calculate Trapezoid Area: Formula, Steps & Examples
Learn how to calculate Trapezoid Area — the formula explained step by step, with worked examples and a free calculator to check your answer.