Problems
The area of a pyramid
The area of a pyramid
A triangular pyramid is given the coordinates of its vertices A(x1
; y1
; z1
), B(x2
; y2
; z2
), C(x3
; y3
; z3
), S(x4
; y4
; z4
). Find the total surface area of the pyramid.
Input
In four lines given the coordinates x, y and z of the pyramid vertices. All input data are integers, not exceeding 100 by absolute value.
Output
Print the total surface area of the pyramid, rounded to the nearest tenth.
Input example #1
-3 0 0 0 6 0 3 0 0 0 2 5
Output example #1
69.8