This site has a good method
Area of a Triangle via the Cross Product
The points A,B and C have position vectors given respectively
a = ( 7i + 4j -2k) b= ( 5i + 3j - 3k) c= ( 6i + 5j - 4k)
a) Find the angle BAC
b) Find the area of the triangle ABC
i have dont part a) and got 60 degrees but i cant do part b)
thanks in advance!
This site has a good method
Area of a Triangle via the Cross Product
Hello, Oasis1993!
You are expected to know this fact:The points A,B and C have position vectors given respectively:
. .
b) Find the area of
The area of the parallelogram determined by two vectors
. . is the magnitude of the cross product of the two vectors.Code:* . . . . . . / . v / . / . * - - - - - * u Area = |u x v|
Hence, the area of the triangle determined by two vectors is: .
Let: .
Then: .
. .