00:01
We are given the vertices of a triangle.
00:03
We're asked to find the area of this triangle.
00:07
The vertices are 2, 3, negative 5, negative 2, negative 2, 0, and 306.
00:25
Now, in order to find the area of this triangle, we'll find half the area of the parallelogram associated with this triangle.
00:37
To find the area of this parallelogram, we'll find the cross product of the two vectors spanning the parallelogram.
00:45
So these two vectors, which i'll call u and v, well, u is the vector from the first point to the second, and v is the vector from the first point to the third.
00:57
And so in component form, u is, using terminal point minus initial point, negative 2 minus 2, negative 2 minus 3, and 0 minus negative 5, which is equal to negative 4, negative 5, 5.
01:17
Likewise, using terminal minus initial, v is equal to 3 minus 2, 0 minus 3, and 6 minus negative 5.
01:31
This is equal to 1, negative 3, 11.
01:44
And so the area of this triangle is half the area...