Parallelogram Problem: Finding Side AD When Area = 40 cm² and Height = 4 cm

To solve this problem, we'll use the area formula for a parallelogram:

• The given area of the parallelogram is 40 cm².
• The height, perpendicular to the base $AD$, is 4 cm.
• We need to find the length of $AD$, the base of the parallelogram.

The formula for the area of a parallelogram is:

$\text{Area} = \text{base} \times \text{height}$

We can rearrange this formula to solve for the base:

$\text{base} = \frac{\text{Area}}{\text{height}}$

Substituting the given values into the formula, we get:

$\text{base} = \frac{40 \, \text{cm}^2}{4 \, \text{cm}}$

Calculating this gives us:

$\text{base} = 10 \, \text{cm}$

Therefore, the length of $AD$ is \textbf{\( 10 } \, \text{cm} \).