Explain why 4/10 ÷ 2 and 4/10 × 1/2 both equal 2/10

They are both equal to 2/10 because 4/10 divided by 2 is the same as 4/10 x 1/2

area of part 1:

a1=base*height/2=(8+2)*(8-2-2-1)/2=10*3/2=15 ft^2

area of part 2:

a2=length*width=(8+2)*1=10 ft2

area of part 3:

a3=length*width=8*2=16 ft2

total shaded area : a1+a2+a3=41 ft2

total area of the reactangle : a=16*8=128 ft2

total area of the nonshaded region : 128-41=87 ft2

the answer will be the last one