Calculate AC Length in Deltoid ABCD with Area 28 cm² and Diagonal DB = 4

To calculate the length of the diagonal $AC$, we start by using the area formula for a deltoid, which involves its diagonals. The area $A$ of a deltoid is given by:

$A = \frac{1}{2} \times AC \times DB$

Given:

• The area of the deltoid $A = 28 \, \text{cm}^2$.
• The length of diagonal $DB = 4 \, \text{cm}$.

We can plug these values into the formula:

$28 = \frac{1}{2} \times AC \times 4$

Solving for $AC$:

$28 = 2 \times AC$

Divide both sides by $2$:

$AC = \frac{28}{2} = 14$

Therefore, the length of side $AC$ is 14 cm.