From the image you've uploaded, you're asking to calculate the surface area of a rectangular prism (balok) with the dimensions of 9 cm, 8 cm, and 4 cm.

To find the surface area of a rectangular prism, the formula is: $\text{Surface Area} = 2(lw + lh + wh)$ where $l$, $w$, and $h$ are the length, width, and height of the prism respectively.

Given:

• $l = 9 \, \text{cm}$
• $w = 8 \, \text{cm}$
• $h = 4 \, \text{cm}$

Substituting these values into the formula, we get: $\text{Surface Area} = 2((9 \times 8) + (9 \times 4) + (8 \times 4))$

Let's calculate this.The surface area of the rectangular prism with dimensions $9 \, \text{cm} \times 8 \, \text{cm} \times 4 \, \text{cm}$ is $280 \, \text{cm}^2$.

Would you like any further details on this calculation, or do you have any other questions?

1. How would the surface area change if one dimension is doubled?
2. What would be the surface area if all dimensions were increased by 2 cm each?
3. How does changing the height affect the total surface area more than changing the width?
4. Would you like to learn how to calculate the volume of this rectangular prism?
5. How would the surface area calculation change if the shape were a cube instead of a rectangular prism?

Tip: When calculating the surface area of any prism, always verify the dimensions twice to avoid any calculation errors.