Jajar Genjang

Jajar genjang termasuk turunan segiempat yang mempunyai ciri khusus.

Jajar genjang dengan empat rusuk yang sama panjang disebut belah ketupat.

Keliling

${\displaystyle K=2\cdot (s1+s2)}$ 

Luas

${\displaystyle L=a\cdot t}$ 

Tinggi

${\displaystyle h_{a}=b\cdot \sin(\alpha )}$ 

${\displaystyle h_{b}=a\cdot \sin(\beta )}$ 

Diagonal

${\displaystyle {\begin{array}{ccl}e&={\sqrt {a^{2}+b^{2}-2\cdot a\cdot b\cdot \cos(\beta )}}\\&={\sqrt {a^{2}+b^{2}+2\cdot a\cdot b\cdot \cos(\alpha )}}\end{array}}}$ 

${\displaystyle {\begin{array}{ccl}f&={\sqrt {a^{2}+b^{2}-2\cdot a\cdot b\cdot \cos(\alpha )}}\\&={\sqrt {a^{2}+b^{2}+2\cdot a\cdot b\cdot \cos(\beta )}}\end{array}}}$ 

Sudut interior

${\displaystyle \alpha =\gamma ,\quad \beta =\delta ,\quad \alpha +\beta =180^{\circ }}$ 

Persamaan jajar genjang

${\displaystyle e^{2}+f^{2}=2\cdot (a^{2}+b^{2})}$