Parallelogram Calculator

units
Enter side a in units.
units
Enter side b in units.
°
Enter included angle in °.
Math

Parallelogram: calculate results from explicit inputs, with a formula and worked example.

Formula

area = ab sin θ; perimeter = 2(a+b); diagonals = √(a²+b² ± 2ab cos θ)

Example Calculation

Example inputs
  • Side a: 6 units
  • Side b: 4 units
  • Included angle: 30 °

Sides 6 and 4 enclosing 30° give area 12 and perimeter 20.

Frequently asked questions

How do I use this calculator?

Enter side a, side b, included angle. The result updates automatically. Use Reset to restore the example values.

What method does it use?

area = ab sin θ; perimeter = 2(a+b); diagonals = √(a²+b² ± 2ab cos θ). Euclidean geometry. Use one consistent length unit; areas and volumes use its square and cube. Degenerate shapes are rejected. Very thin shapes may lose floating-point precision.

Why might a rounded result differ?

The calculation keeps full numeric precision internally, then rounds the displayed result. Rounding intermediate steps by hand can produce a slightly different answer.

Are my inputs saved online?

No. This calculator processes your inputs in your browser. A recently used list stores only calculator names on this device, not your entered values.

Check the assumptions and units before using this result. Read about calculation methods.