bg math, stupid trig question halp

[Vandole]

i can't find my notes on area for Area formula and semi-perimeters,

the problems ive been doing have using the formula

a=(1/2)absinC no problem,

but now that i'm working on problems that are just 3 distances,

ex:
a = 12m
b = 16m
c= 25m
Find the area of each triangle ABC.

what do?

spoilar ans if you know how to do it and wanna check before calling me stupid

Spoiler: show

78 m^2

[Kaylia]

i can't find my notes on area for Area formula and semi-perimeters,

the problems ive been doing have using the formula

a=(1/2)absinC no problem,

but now that i'm working on problems that are just 3 distances,

ex:
a = 12m
b = 16m
c= 25m
Find the area of each triangle ABC.

what do?

spoilar ans if you know how to do it and wanna check before calling me stupid

Spoiler: show

78 m^2

S = b* h /2


To find h, you split the triangle in 2 right triangle

According to pythagora theorem (where x is the base of one triangle, and 25-x the base of the 2nd right triangle)

x²+h²=12²
(25-x)²+h²=16²
2 equation, 2 variables
x=10.26
h=6.22


s= 77,8


probably fucked up..it feels off (I blame window's shitty calculator)

[Vandole]

i figured it out, yay for stupid questions. thanks though kaylia