A different triangular-based prism has the base shown in the diagram on the right - Junior Cycle Mathematics - Question 12 - 2016

To find the area of face A:

The area of a rectangle is given by:

$\text{Area}_A = x \times h = 10.23 \times 12 = 122.76 \, \text{cm}^{2} \approx 123 \, \text{cm}^{2} \text{ (to the nearest cm)}$

For face B, which is also a rectangle:

$\text{Area}_B = 7 \times h = 7 \times 12 = 84 \, \text{cm}^{2}$

For face C, we can use the area formula for a triangle:

$\text{Area}_C = \frac{1}{2} \times \text{base} \times \text{height} = \frac{1}{2} \times 7 \times 12 = 42 \, \text{cm}^{2}$

Thus, the areas are:

• A: 123 cm²
• B: 84 cm²
• C: 42 cm².