Calculate Deltoid Area: Using Diagonals AC=7cm and DB=5cm

A deltoid (also called a kite) is a quadrilateral where the diagonals are perpendicular to each other. The area formula $A = \frac{1}{2} \times d_1 \times d_2$ works because the perpendicular diagonals divide the deltoid into four right triangles.

No! This diagonal formula only works for shapes where diagonals are perpendicular, like deltoids, rhombuses, and kites. For rectangles or parallelograms, use length × width instead.

When you multiply the diagonals, you're finding the area of a rectangle that contains the deltoid. Since the deltoid takes up exactly half of that rectangle's area, we divide by 2.

Then it's not a true deltoid! You'd need a different formula involving the sine of the angle between diagonals: $A = \frac{1}{2} \times d_1 \times d_2 \times \sin(\theta)$.

Think of it as "half of diagonal times diagonal". You can also remember that deltoid area is similar to triangle area $(\frac{1}{2} \times base \times height)$, but with both diagonals!