Answer:
Option B

Explanation:
The area of quadrilateral ABCD is equal to the area of triangle ABD plus the area of triangle ADC
we know that
Heron's Formula is a method for calculating the area of a triangle when you know the lengths of all three sides.
Let
a,b,c be the lengths of the sides of a triangle.
The area is given by:

where
p is half the perimeter

step 1
Find the area of triangle ABD
we have



Find the half perimeter p

Find the area




step 2
Find the area of triangle ADC
we have



Find the half perimeter p

Find the area




step 3
Find the total area
