Use an area formula where perimeter is required, or vice versa.
An error-pattern drill: practice spotting and avoiding this specific SHSAT trap.
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A rectangle is 5 by 8. Its area is \(5 \times 8 = 40\) square units. Its perimeter is \(2(5 + 8) = 26\) units. Both numbers come from the same two sides, so it is easy to give one when the question asks for the other.
Area measures the space inside a shape (carpet, paint, tiles). Perimeter measures the distance around it (fence, trim, border). Circles have the same split: the area is \(\pi r^2\), the circumference is \(2\pi r\), and an arc is a part of the circumference.
Check habits:
Area \(= l \times w = 14 \times 25 = 350\) sq in. (Adding and doubling, \(2(14 + 25)\), gives the perimeter, 78. Adding the two sides gives 39. Using the triangle formula \(\dfrac{1}{2}lw\) gives 175.)
Circumference \(= 2\pi r = 24\pi\). The arc is \(\dfrac{240}{360}\) of it: \(\dfrac{240}{360} \times 24\pi = 16\pi\) in. (Using \(\pi r\) and forgetting the 2 gives \(8\pi\). Using the area \(\pi r^2\) gives the sector's area, \(96\pi\). Stopping at the whole circumference gives \(24\pi\).)
Shaded area \(= \text{rectangle} - \text{circle} = 270 - 3.14(4)^2 = 270 - 50.24 = 219.76\) sq in. (Adding the circle instead of subtracting it gives 320.24. Subtracting the circumference, \(2(3.14)(4) = 25.12\), instead of the area gives 244.88. Forgetting to subtract the circle gives the rectangle's area, 270.)