Trapezoid area
Trapezoid area A = (a + b)·h / 2: enter the two bases and the height to get the area plus the median and the base sum; values are rounded to 6 decimals and any non-positive value is rejected.
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Result
One quantity per line, ready to copy.
Enter a top base to calculate
What this tool does
- Compute the area of a trapezoidal plot, embankment section or metal part, and get the median for layout.
- Set both bases equal to check a rectangle, or use a very small top base to approximate a triangle.
- Verify the formulas: area (a+b)·h/2 and median (a+b)/2.
Example
Input
1
Output
上底 1 下底 1 高 1 的梯形面积：1 中位线 (a+b)/2：1 两底和 a+b：2 长度单位 u，面积 u²，体积 u³
With bases 2 and 4 and height 3 the area is 9, the median 3 and the sum 6 — all exact. Setting both bases equal degenerates into a rectangle.
Frequently asked questions
Which base is which?
The top base is the shorter one (drawn above) and the bottom base the longer one; they must be parallel. The formula is symmetric, so swapping them keeps the area and only changes the labels.
What is the median for?
It joins the midpoints of the legs and equals (a+b)/2. The area is also median × height, which is handy for layout and for catching arithmetic slips.
What if the top base is 0?
It reports an error. A zero base turns the trapezoid into a triangle — the formula still holds, but non-positive input is rejected here; use the equilateral triangle or geometry calculator instead.
Keywords：梯形面积trapezoid area梯形中位线几何计算上底下底