It's obviously none of the above because the true area will have a square root of 3 in it because of the equilateral triangle. They want us to find the approximate area. When I was in school the difference between an approximation and the exact answer was greatly stressed but that seems to be fading of late.
That's a rectangle less an equilateral triangle. The area of an equilateral triangle is [tex] \dfrac{\sqrt{3}}{4} s^2 [/tex] which is easily derived but I won't bother here.
[tex]A = 18(8) - \dfrac{\sqrt 3}{4} (8^2) = 144 - 16 \sqrt 3 \approx 116.3 [/tex]
Answer: b
