Description for Correct answer:
Given that, area = 40 sq cm. base = 28 cm and height = perpendicular = ?

Area = \( \Large \frac{1}{2}\times Base\times Perpendicular \)

=> 40 = \( \Large \frac{1}{2}\times 28\times Perpendicular \)

Perpendicular =\( \Large \frac{40}{14}=\frac{20}{7} \)

=\( \Large 2\frac{6}{7} \)cm