Question

SOMEONE HELP ME PLEASE

http://www.thestudentroom.co.uk/attachment.php?attachmentid=145656&d=1336078105

The diagram shows an open container constructed out of 200 cm2 of cardboard. The two vertical end pieces are isosceles triangles with sides 5x cm, 5x cm and 8x cm, and the two side pieces are rectangles of length y cm and width 5x cm, as shown. The open top is a horizontal rectangle.

Show that http://www.thestudentroom.co.uk/latexrender/pictures/6a/6aef7d7646ee9c6aa0402ff57f86face.png

Show that the volume, V cm3, of the container is given by V = 240x − 28.8x^3

Answer 1

`The diagram shows an open container constructed out of 200 cm2 of cardboard.`

interpret this line^^

Answer 2

that means the area of that container is 200cm2, yes ?

Answer 3

and notice that the container is made up of below shapes :
1) two triangles of sides : 5x, 5x, 8x
2) two reactangles of sides : 5x, y

Answer 4

can you find the area of them ?

Answer 5

@Lama97 please participate here, so that you may be cleared with the points...

Answer 6

Sorry for being late.

Well yes, but first I need to find the triangle height using pythagoras theorem.
5^2=4^2 + a^2
a=3

Area of 2 triangles
(8*3)\2 = 12 *2 = 24

Area of 2 rectangles
5xy *2 = 10xy

Answer 7

How can I show the volume then ?

Answer 8

Refer to the Mathematica attachment.