Triangle Area via Cross Product

Problem

Compute the area of the triangle with 3D vertices p, q, r:

area = 0.5 * ||(q - p) x (r - p)||_2

A degenerate (collinear) triangle has area 0.0.

Hint

Half the area of the parallelogram spanned by q - p and r - p.

case 1

in: [[0,0,0],[1,0,0],[0,1,0]]

expected: 0.5

case 2

in: [[1,1,1],[2,1,1],[1,3,1]]

expected: 1

case 3

in: [[0,0,0],[1,1,1],[2,2,2]]

expected: 0

case 4

in: [[0,0,0],[2,0,0],[0,2,0]]

expected: 2

Starter codePython

def triangle_area(p, q, r):
    # Your code here
    pass

4 test cases · run your code against them in the editor