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- Sep 4th 2012, 04:02 PM #1

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## please help me!!

Hi can someone help me solve this problem,please!!

A piece of cardboard measures 40 cm by 40 cm. An open-topped box is to be constructed by removing a square with side length of 8 cm from each corner and folding up the edges.

**a)**Find the surface area of the box.**b)**Find the volume of the box.

- Sep 4th 2012, 04:14 PM #2
## Re: please help me!!

- Sep 4th 2012, 09:10 PM #3

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## Re: please help me!!

Hello, allison!

A piece of cardboard measures 40 cm by 40 cm.

An open-topped box is to be constructed by removing a square with side length of 8 cm

from each corner and folding up the edges.

(a) Find the surface area of the box.

This is simple!

You start with a 40-by-40 piece of cardboard.

Its area is:

You remove four 8-by-8 squares.

So you remove:

So the surface area of the box must be:

(b) Find the volume of the box.

Did you make any sketches?

Code:: - - - 40 - - - - : - *---*-----------*---* - : |///| |///| 8 : *---* - - - - - *---* - : | : : | : : | : : | : 40 | : : | 24 : | : : | : : | : : | : . : *---* - - - - - *---* - : |///| :///| 8 - *---*-----------*---* - : 8 : - 24 - - : 8 :

. . and the sides are folded upward on the dotted lines.

The open-top box looks like this:

Code:*-----------* /| /| / * - - - - / * / / / / *-----------* / 24 8| |/ *-----------* 24