we have that
the area of the arrow is equal to the area of two rectangles plus the area of two right triangles
so
step 1
Find out the area of the two rectangles
A=2[(18)(5)]
A=180 ft2
step 2
Find out the area of the two right triangles
A=2[(1/2)(24-18)(5+5)]
A=2[(1/2)(6)(10)]
A=60 ft2
therefore
total area is
A=180+60
A=240 ft2