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Parallelogram Calculator

Computes the area of a parallelogram from base and height and, when the slanted side is given, its perimeter, the acute angle between base and side in degrees, and both diagonals.

When to use

You need the area, perimeter, angles or diagonals of a quadrilateral whose opposite sides are parallel (including rhombi).

Do not use when: All angles are right angles (use rectangle) or only one pair of sides is parallel (use trapezoid).

Formula

area = base × height; perimeter = 2 × (base + side); angle_deg = asin(height / side); diagonals = √(base² + side² ± 2·base·√(side² − height²))

Inputs

ParameterTypeUnitRequiredDescription
basenumberunitsyesLength of one side chosen as the base. Range: > 0
heightnumberunitsyesPerpendicular distance between the base and its opposite side. Range: > 0
sidenumberunitsnoLength of the slanted side adjacent to the base (optional; must be at least the height). Range: > 0

Outputs

OutputTypeUnitDescription
areanumberunits²base × height.
perimeternumberunits2 × (base + side), only when side is given.
angle_degnumberdegreesAcute angle between base and side = asin(height / side); the obtuse angle is 180° minus this.
diagonal_longnumberunits√(base² + side² + 2·base·√(side² − height²)).
diagonal_shortnumberunits√(base² + side² − 2·base·√(side² − height²)).

Example

Base 8, height 5, side 6: {"base":8,"height":5,"side":6}{"area":40,"perimeter":28,"angle_deg":56.4427,"diagonal_long":12.372,"diagonal_short":6.8508}

Base 10, height 3: {"base":10,"height":3}{"area":30}

GET https://tttkmbb.com/api/v1/calculate/parallelogram?base=8&height=5&side=6

Machine access

Sources

FAQ

Why must the side be at least the height?

The height is the perpendicular distance between the parallel sides, so the slanted side can never be shorter than it; side = height gives a rectangle.

How do I compute a rhombus?

Enter side = base. The area is still base × height, or you can use diagonal_long × diagonal_short / 2.

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