I think I am adding this wrong.. help

(18)

Here is one way to look at it....

This kite is made up of four right triangles:

The total area of the kite is the sum of the areas of these four triangles.

area of kite  =  area of red △ + area of blue △ + area of green △ + area of purple △

Now we need to find the area of each triangle.

area of a triangle  =  (1/2)(length of base)(height)

area of red triangle  =  (1/2)(7)(3)

area of blue triangle  =  (1/2)(7)(3)

area of green triangle  =  (1/2)(3.5)(3)

area of purple triangle  =  (1/2)(3.5)(3)

Now we can find area of kite.

area of kite  =  (1/2)(7)(3) + (1/2)(7)(3) + (1/2)(3.5)(3) + (1/2)(3.5)(3)

area of kite  =  (7)(3) + (3.5)(3)

area of kite  =  3(7 + 3.5)

area of kite  =  3(10.5)

area of kite  =  31.5        That is in ft²