00:01
We are given the vertices of a triangle.
00:03
We're asked to find an area of this triangle.
00:07
The vertices are 1, negative 4, 3, 202, and negative 2 ,20.
00:28
To find the area of the triangle, first we'll find the area of the parallelogram, of which this triangle is half the area.
00:38
To do this, we'll have to find the cross product of two vectors, which contain the sides of the parallelogram.
00:50
So i'm going to find two vectors, u and v.
00:54
So u is the vector from the first point to the second, and b is the vector from the first point to the third.
01:00
So in component form, u is using terminal minus initial, 2 minus 1, 0 minus negative 4, 2 minus 3.
01:10
This is equal to 1, 4, negative 1, and v is equal to using terminal minus initial, negative 2 minus 1, 2 minus negative 4, and 0 minus 3.
01:34
And this simplifies to negative 3, 6, negative 3...