# Parallelogram calculator

Enter what you know about the parallelogram and let the tool calculate the rest.
 Side a: Side c: Angle u: Angle x: Height: Perimeter: Area:
Note: You can use mathematical expressions.

A parallelogram has four sides where the opposite sides are parallel. A rectangle can be thought of as a parallelogram where all angles are right angles (90°). The parallelogram is a special case of the trapezium.

The way the tool works is by reading the attributes that has been entered and using them to calculate the unknown attributes of the parallelogram. If there is not enough information to calculate a certain attribute it will be displayed as a question mark. For example, if only the height and side a is known it is possible to calculate the area but nothing else. If some of the values contradict each other so that it is impossible to construct a valid parallelogram the tool will instead display an error message.

You might wonder why the letters used for the sides and angles skip some letters in the alphabet. The reason for this is to make it more consistent with the trapezium tool in the hope that it will be less confusing in case you use both tools.

Geometric shapes: Circle, Parallelogram, Rectangle, Square, Trapezium, Triangle