Calculate the area, perimeter, diagonals, and angles of an irregular trapezoid from two parallel sides and two legs or height. Includes visual comparison bars, presets, and a reference table.
An irregular trapezoid (also called a scalene trapezoid) is a four-sided figure with exactly one pair of parallel sides and two non-equal legs. Unlike an isosceles trapezoid, the legs can have different lengths, creating asymmetric shapes common in architecture, land surveying, and engineering design.
This calculator lets you find the area of any irregular trapezoid using two methods: (1) enter all four side lengths, or (2) enter the two parallel sides plus the perpendicular height. It computes the area using the classic formula A = (a + b) / 2 × h, and also derives the height from four sides using the coordinate geometry approach.
Beyond the area, the tool reports the full perimeter, both diagonal lengths, all four interior angles, and the median (midsegment). A visual bar chart compares the key measurements at a glance, and a reference table summarizes the main trapezoid families so you can identify your shape. Eight built-in presets let you explore common configurations instantly, making this calculator valuable for students learning quadrilateral geometry, engineers designing irregular cross-sections, and surveyors measuring trapezoidal parcels of land.
Irregular Trapezoid Area problems often require several dependent steps, and a small arithmetic slip can propagate through every derived value. This calculator is tailored to that workflow: you enter parallel side a (value), parallel side b (value), leg c (value), and it returns area, perimeter, height, median (midsegment) in one consistent pass. It is useful for homework checks, worksheet generation, tutoring walkthroughs, and fast field/design estimates where you need reliable geometry results without rebuilding the full derivation each time.
Area = (a + b) / 2 × h, where a and b are the parallel sides and h is the perpendicular height. When four sides are given, h is derived from Heron-style coordinate placement.
Result: Area ≈ 32 cm²
With parallel sides 10 and 6, and equal legs 5 each, the height is 4, giving area = (10 + 6)/2 × 4 = 32 cm².
This irregular trapezoid area tool links the entered values (parallel side a (value), parallel side b (value), leg c (value), leg d (value)) to the target geometry relationships used in class and practice problems. Instead of solving each intermediate step manually, you can validate setup and arithmetic quickly while still tracing which measurements drive the final result.
Formula focus: the calculator formula
Irregular Trapezoid Area shows up in school geometry, technical drafting, construction layout checks, and early engineering design estimates. When values are changed repeatedly, the calculator helps you compare scenarios quickly and see how sensitive the shape is to each dimension.
Start with the primary outputs (area, perimeter, height, median (midsegment)) and then use the remaining cards/tables to confirm consistency with your diagram. Keep units consistent across inputs, and round only at the end if your assignment or project specifies a fixed precision.
An irregular (scalene) trapezoid has two parallel sides of different length and two non-equal legs, so it has no line of symmetry. Use this as a practical reminder before finalizing the result.
Place side a along the x-axis, project leg c from one end and leg d from the other, then solve for the y-coordinate using the Pythagorean theorem on each leg triangle. Keep this note short and outcome-focused for reuse.
Yes — if one leg is perpendicular, the height equals that leg length. You can enter it in either mode.
The calculator checks geometric feasibility. If the height squared is negative, the sides cannot close into a valid trapezoid and no result is shown.
Under the inclusive definition (at least one pair of parallel sides), yes. A parallelogram has a = b, so the formula still applies.
After placing the trapezoid in a coordinate system, each diagonal is the distance between opposite vertices computed with the distance formula. Apply this check where your workflow is most sensitive.