WOLFRAM|DEMONSTRATIONS PROJECT

Signed 2D Triangle Area from the Cross Product of Edge Vectors

triangle
edge vectors
cross product
axes
a = {-3,-3}
b = {3,-3}
c = {3,3}

Note: to fit in the cross product, one Z axis unit = 10 X / Y axis units.

The signed area of a triangle

T

in the

x

-

y

plane with vertices

a

,

b

,

c

is given by half the

z

component of the cross product

(

v



w

)

z

of the edge vectors

v

=b-a

and

w

=c-a

.