Find the area of quadrilateral ABCD.

Step-by-step explanation:

We can use Heron's formula to calculate area of triangles:

  where:

a, b, c  - sides of triangle

s  - semi-perimetr of triangle  {(a+b+c):2}

ΔACD:

a = 4.39 ,   b = 3.42  ,  c = 4.57

s = (4.39 + 3.42 + 4.57)÷2 = 12.38÷2 = 6.19

ΔACD:

a = 5.44 ,   b = 7.84 ,   c = 3.42

s = (5.44 + 7.84 + 3.42)÷2 = 16.7÷2 =

dhdhth

step-by-step explanation:

c. (3,2,6) is the answer.