← Trigonometriset funktiot · Lukion taulukot · Trigonometriset funktiot (Trigonometria) →
1. sinα=ac{\displaystyle \sin \alpha ={\frac {a}{c}}}
2. cosα=bc{\displaystyle \cos \alpha ={\frac {b}{c}}}
3. tanα=ab{\displaystyle \tan \alpha ={\frac {a}{b}}}
4. α=90∘−β{\displaystyle \alpha =90^{\circ }-\beta }
5. a2+b2=c2{\displaystyle a^{2}+b^{2}=c^{2}}
6. Ala A=12ab{\displaystyle A={\frac {1}{2}}ab}
1. Sinilause
2. Kosinilause
3. Ala A=12absinγ=2r2sinαsinβsinγ=pρ{\displaystyle A={\frac {1}{2}}ab\sin \gamma =2r^{2}\sin \alpha \sin \beta \sin \gamma =p\rho } , missä p=12(a+b+c){\displaystyle p={\frac {1}{2}}(a+b+c)} .