What is the area of a quadrilateral whose vertices are given?

Question

What is the area in square units, of a quadrilateral whose vertices are (5,3), (6,-4), (-3,-2), (-4,7)?

Answer 1

the quadritlateral can be split into 2 triangles (5,3), (6,-4), (-3,-2) and (5,3), (6,-4), (-4,7) 

 

use heron's law 

 

Area triangle A - SQRT ((s(s-a)(s-b)(s-c))

s (semi perimeter)=1/2 (a+b+c)

 

calculate a,b,c (lenghts of sides of triangle) from the coordinates given, insert into equation

 

Answer is 69