find the area of traingle ABC if a = 10cm ,b = 3cm and c= 9cm
help please <3
and i have my final exam tomorrow... so if u want to help me tonight for a while private message me we can work on msn together! yayyy ^_^ lolll
Hero's (Heron's?) formula says that the area of a triangle is
$\displaystyle A = \sqrt{s(s - a)(s - b)(s - c)}$
where
$\displaystyle s = \frac{a + b + c}{2}$
is called the semi-perimeter.