Find the area of he triangle?

Question

For the given points A, B, and C find the area of the triangle with vertices A, B, and C.

A(6, 7, 5), B(6, 17, 3), C(4, 9, 3).

The area is ?

Answer 1

Area = (1/2)||AB X AC||

AB = (0,10, -2) AC = (-2, 2, -2)

| i j k |

|0 10 -2 | = (-20 +4)i +4j + 20k

|-2 2 -2 |

||AB X AC|| = √(16² + 4² + 20²) = 25.9

Area = 25.9/2 = 12.96