# Math Help - identify the data required & determine the volume of two compund solid bodies

1. ## identify the data required & determine the volume of two compund solid bodies

1)

how do i work out the volume?
do i work out the rectangle first then the semi circle?

http://i10.photobucket.com/albums/a1...5/DSC00515.jpg

2)
if the template is 3mm think, what is the volume in cubic millimetres?
do i split it into 2 rectangles, triangle & a circle?

http://i10.photobucket.com/albums/a1...5/DSC00517.jpg

cheers all

2. Originally Posted by turbod15b
1)

how do i work out the volume?
do i work out the rectangle first then the semi circle?

http://i10.photobucket.com/albums/a1...5/DSC00515.jpg
cheers all
Work out the area of the crossection (the semi-circle or radius 8 cm (0.08m)
plus the rectangle 16 by 12 cm (0.16 by 0.12 m, but do it in metres) then multiply by the length.

This will give the volume in cubic metres.

RonL

3. Originally Posted by turbod15b
2)
if the template is 3mm think, what is the volume in cubic millimetres?
do i split it into 2 rectangles, triangle & a circle?

http://i10.photobucket.com/albums/a1...5/DSC00517.jpg

cheers all
Split it us as you say to find the area, then multiply by the thickness.

As I'm sure you know the area is the sum of the areas of the rectangles and the
triangle minus the area of the circle.

RonL

4. 2)

area of circle 3.141 * 25 squared = 1963.125cm2

area of rectangles = Length * Width or Base * Height

220mm * 30mm = 6600mm2 or 66cm2

130mm * 30mm = 3900mm2 or 39cm2

area of triangle = 1/2 * base * height
1/2*130mm*125mm=8125mm2

how do i find out the volume in cubic millimetres if the template is 3mm thick?

5. Hello, turbod15b!

Your dimensions are a bit off . . .
Code:
          30
*-------*
|       |
|       |45
|       |
|       *
170 |       : *
|  (2)  :   *
|       :     *
|       :125    *
|       :         *
|       :    130    *         60
* - - - * - - - - - - *---------------*
|                                     |
30|               (1)                   |30
|                                     |
*-------------------------------------*
220

Rectangle (1) : . $220 \times 30\:= 6600\text{ mm}^2$

Rectangle (2): . $170 \times 30 \:=\:5100\text{ mm}^2$

Triangle: . $\frac{1}{2}(130)(125) \:=\:8125\text{ mm}^2$

Circle: . $\pi(25^2)\:\approx\:1963.5\text{ mm}^2$

Total area: . $6600 + 5100 + 8125 - 1963.5\:=\:17,861.5\text{ mm}^2$

Total volume: . $17,861.5\text{ mm}^2 \times 3\text{ mm} \;=\;53,584.5\text{ mm}^3$

6. ty