Answer
$14a^{2}b$
Work Step by Step
$\text{Area of the rectangle}= \text{length}\times\text{width}$
$\implies \text{ length}=\frac{\text{Area}}{\text{width}}=\frac{112a^{3}b^{2}}{8ab}$
$=(\frac{112}{8})(\frac{a^{3}}{a})(\frac{b^{2}}{b})=14a^{2}b$
