## Thursday, March 25, 2010

### Deniel's surface area growing post

Okay guys here is my surface area growing post about right rectangular prism, right triangles, and cylinders

Here is my first surface area question:
Okay here is what I did:

front:
13.5 cm x 18.5cm =area 13.5 x 18.5= 249.75cm x 2 = 499.5cm
side:
5 cm x 13.5cm =area 13.5 x 5= 67.5cm x 2 = 135cm
length:
18.5 cm x 5cm =area 18.5 x 5= 92.5cm x 2= 185cm

499.5+135+185= 819.5
Area= 819.5cm

Here is my second question:
Okay so here's what I did:

A= l x w A= (b x h) / 2
A= 9 x 3 A=(3 x 2.6) / 2
A= 27 The area on one rectangle is 27m A=7.8 / 2
A=3.9 and its the area of one triangle

Surface Area= (3 x rectangle) + (2 x area of triangle)
= (3 x 27) + (2 x 3.9)
= 81 + 7.8
= 88.8
So the surface area is 88.8 centimetre squared.

Here's my third question:
Here's what I did:
Determine the radius of each circle:
7.5 / 2 = 3.75 so 3.75 is the radius of each circle

Find the area of the circle
A=π x r2
A=3.14 x 3.75 x 2
A= 44.15625 so the area of one circle is 44.15625 x 2 = 88.3125 for both circles.

Find the area of the rectangle using the circumference of the circle.
A= l x w
A=(π × d) × w
A= 3.14 × 7.5 × 11
A= 259.05
The area of the rectangle is approximately 259.05 cm2.

Calculate the total surface area.
Surface area = 88.3125 + 259.05
= 347.3625
The total surface area is approximately 347.36 cm2

So here is my surface area growing post :)

#### 1 comment:

1. This comment has been removed by the author.

## Calculator

powered by math calculator at calculator.net

## Technorati Tags

© Blogger templates Psi by Ourblogtemplates.com 2008

Back to TOP