Ans: A
Note that the maximum absolute error is $0.5\text{ cm}$. Then, the least possible area
Note that the maximum absolute error is $0.5\text{ cm}$. Then, the least possible area
$\begin{array}{cl}
= & (8-0.5) \times (10 – 0.5) \\
= & 71.25 \text{ cm}^2
\end{array}$
And the greatest possible area
$\begin{array}{cl}
= & (8+0.5) \times(10+0.5) \\
= & 89.25 \text{ cm}^2
\end{array}$
Therefore, $71.25 \le x < 89.25$.
