X8.8.PS-16
The bottom part of this block is a rectangular prism. The top part is a square pyramid. You want to cover
the block entirely with paper. How much paper do you need? Use pencil and paper to explain your
reasoning.
You need cm² of paper.
3mm
(The figure is not to scale)

X88PS16 The bottom part of this block is a rectangular prism The top part is a square pyramid You want to cover the block entirely with paper How much paper do class=

Respuesta :

Answer: 57 cm²

Step-by-step explanation:

To answer this question, we need to find the surface area of the figure.

First, we will find the surface area of the bottom part, the rectangular prism. We will use the given formula. However, we do not count the top side since it is connected to the bottom part. We will subtract this.

       SA = 2(wl + hl + hw)

       SA = 2((3 cm)(3 cm) + (2 cm)(3 cm) + (2 cm)(3 cm))

       SA = 42 cm²

       SA = 42 cm² - 9 cm² = 33 cm²

Next, we will find the surface area of the top part, the square pyramid. We know we have four congruent triangles. We will not count the square base since it is connected to the bottom part.

       SA = 4 * ([tex]\frac{bh}{2}[/tex])

       SA = 2 * (bh)

       SA = 2 * ((3 cm)(4 cm))

       SA = 2 * (12 cm²)

       SA = 24 cm²

Lastly, we will add these two parts together.

        33 cm² + 24 cm² = 57 cm²