35.7k views
4 votes
Suppose the length and width of the box in exercise 12 double. Does the surface area S double? Explain

10cm 24cm and 27cm are the lengths in exercise 12

User Mrog
by
8.8k points

1 Answer

3 votes
No, it does not.

In general, surface area is the sum of the areas of each face of a prism. In a rectangular prism, we have length, width, and height.

The area of the bottom of the prism and the top of the prism is the same, and can be represented as l*w. This means that together, it is 2lw.

The area of the left and right faces of the prism is the same, and can be represented as l*h. This means that together, it is 2lh.

The area of the front and back faces of the prism is the same, and can be represented as w*h. This means that together, it is 2wh.

This gives us the equation

SA = 2lw+2lh+2wh

If we double the length and width, making them each 2l, we then have:

SA = 2(2l*2w) + 2(2l*h) + 2(2w*h)
= 2(4lw) + 4lh + 4wh
= 8lw + 4lh + 4wh

If the surface area had been doubled, we would expect
4lw + 4lh + 4wh

No, it is not doubled.
User Amitabha Roy
by
8.4k points

Related questions

asked Feb 21, 2022 192k views
Nbbk asked Feb 21, 2022
by Nbbk
8.2k points
1 answer
4 votes
192k views
asked Aug 18, 2022 23.9k views
Jan Galtowski asked Aug 18, 2022
by Jan Galtowski
8.6k points
1 answer
3 votes
23.9k views
asked Jul 7, 2023 176k views
GWed asked Jul 7, 2023
by GWed
9.2k points
1 answer
5 votes
176k views