Pindalad Kolmnurga pindala arvutamise valemid S=c⋅h2\large S= \frac{c \cdot h}{2} S=12⋅a⋅b⋅sinγ , S=12⋅b⋅c⋅sinα , S=12⋅a⋅c⋅sinβ\large S=\frac{1}{2}\cdot a\cdot b\cdot \sin\gamma \ , \ S=\frac{1}{2}\cdot b\cdot c\cdot \sin\alpha \ , \ S=\frac{1}{2}\cdot a\cdot c\cdot \sin\beta S=p(p−a)(p−b)(p−c) , p=a+b+c2\large S = \sqrt{p(p-a)(p-b)(p-c)}\ , \ p=\frac{a+b+c}{2} . S=p⋅r\large S=p \cdot r, kus rr on siseringjoone raadius S=a⋅b⋅c4⋅R\large S= \frac{a \cdot b \cdot c}{4 \cdot R} , kus RR kolmnurga ümberringjoone raadius
