Parallelogram

In geometry, a parallelogram is a quadrilateral whose opposite sides are parallel and of equal. Consequently, its opposite angles are congruent. Rhombus, oblongs and squares are all types of parallelogram; all rectangles are also parallelograms.

Formulas

• Area $A=b*h=ab\sqrt{1-\cos^2(\theta)}$

• Diangle lengths $p=\sqrt{a^2+b^2-2ab\cos(\theta)}$ , $q=\sqrt{a^2+b^2+ 2ab\cos(\theta)}$

• Circumradius $R=\sqrt{\dfrac{a^2+b^2}{4\sin^2(\theta)}}$

• Inradius $r=\frac{ab}{a+b}\sin(\theta)$

See also

• Parallelepiped - 3D equivalent