To find the area of a trapezoid, you need the lengths of the two bases (B¹ and B²) and the height (H).
For the given dimensions of 3 cm, 9 cm, and 7 cm, let's assume:
- B¹ = 3 cm (one base)
- B² = 9 cm (the other base)
- H = 7 cm (the height)
Now, we can plug these values into the area formula:
\[ A = \frac{(B¹ + B²)}{2} \times H \]
\[ A = \frac{(3 , \text{cm} + 9 , \text{cm})}{2} \times 7 , \text{cm} \]
\[ A = \frac{12 , \text{cm}}{2} \times 7 , \text{cm} \]
\[ A = 6 , \text{cm} \times 7 , \text{cm} \]
\[ A = 42 , \text{cm}² \]
So, the area of the trapezoid is 42 cm².