Geometry problems 1/21

Concept summary and connections

Heron's formula allows you to compute the area of a triangle from nothing more than the lengths of its sides (and it works for all triangles).

\begin{aligned} let s & = \frac{a + b + c}{2} \\ then [a b c] & = \sqrt{s (s - a) (s - b) (s - c)} \end{aligned}