Area List » area formula http://www.thearealist.com Fri, 03 Feb 2012 07:36:48 +0000 http://wordpress.org/?v=2.8.4 en hourly 1 How do you find the height of a triangle using the area formula? http://www.thearealist.com/area-formula/how-do-you-find-the-height-of-a-triangle-using-the-area-formula http://www.thearealist.com/area-formula/how-do-you-find-the-height-of-a-triangle-using-the-area-formula#comments Fri, 03 Feb 2012 07:36:48 +0000 admin http://www.thearealist.com/area-formula/how-do-you-find-the-height-of-a-triangle-using-the-area-formula I know what the end product is, h = A x .5b , but how do you get to it?

Sadly, no, your end product is wrong.
Here’s how to get the right answer from the formula A= 1/2 * b * h

divide both sides by b ( base length)

A / b = 1/2 * h

finally multiply both sides by 2

2 * A / b = h

h = 2A/b

]]> http://www.thearealist.com/area-formula/how-do-you-find-the-height-of-a-triangle-using-the-area-formula/feed 1 What is the Surface Area Formula of a 3 Dimensional Rectangle? http://www.thearealist.com/area-formula/what-is-the-surface-area-formula-of-a-3-dimensional-rectangle http://www.thearealist.com/area-formula/what-is-the-surface-area-formula-of-a-3-dimensional-rectangle#comments Tue, 17 Jan 2012 03:47:49 +0000 admin http://www.thearealist.com/area-formula/what-is-the-surface-area-formula-of-a-3-dimensional-rectangle I need this for a Larger Problem, but I forgot what this is. The problem is easy if I have this Formula. Can someone give it to me?

It is the sum of all its faces area , and since you have rectangle , there are 6 faces
just simply compute them and add them up
and if you want a formula , then lets assume the dimensions are X , Y and Z
A= 2xy + 2xz + 2zy

]]> http://www.thearealist.com/area-formula/what-is-the-surface-area-formula-of-a-3-dimensional-rectangle/feed 3 How to derive the formula area of triangle=(1/2)bh? http://www.thearealist.com/area-formula/how-to-derive-the-formula-area-of-triangle12bh http://www.thearealist.com/area-formula/how-to-derive-the-formula-area-of-triangle12bh#comments Tue, 03 Jan 2012 06:04:47 +0000 admin http://www.thearealist.com/area-formula/how-to-derive-the-formula-area-of-triangle12bh It don’t want a derivation related to rectangle or parllelogram because its the most basic formula and even the area of rectangle was derived from this formula. So I want a real basic derivation.

It can be derived using integration

consider a line of length dl and having a small thickness dx

the triangle can be assumed to be made from n lines of variable length and thickness dx

since the area covered by line is infinitesimally small it can be assumed as small rectangle having length dl and breadth dx

now area of line = dl.dx

now area of triangle= (within limits 0 to l for dl) and (within limits 0 to h for dx) integration dl.dx

i was able to imagine upto this… this will give u the hint…

]]> http://www.thearealist.com/area-formula/how-to-derive-the-formula-area-of-triangle12bh/feed 2 What is the area formula for a triangle? http://www.thearealist.com/area-formula/what-is-the-area-formula-for-a-triangle http://www.thearealist.com/area-formula/what-is-the-area-formula-for-a-triangle#comments Thu, 13 Oct 2011 04:24:43 +0000 admin http://www.thearealist.com/area-formula/what-is-the-area-formula-for-a-triangle I have to find the area of a triangle, but it didn’t give me the height, just the measure of one base. But the triangle is an equilateral triangle, so is there a special formula that works for equilateral triangles?

The base is the height.
Bh1/2

]]> http://www.thearealist.com/area-formula/what-is-the-area-formula-for-a-triangle/feed 4 How do you create a quadratic equations with this formula: "Area=Length x Width"? http://www.thearealist.com/area-formula/how-do-you-create-a-quadratic-equations-with-this-formula-arealength-x-width http://www.thearealist.com/area-formula/how-do-you-create-a-quadratic-equations-with-this-formula-arealength-x-width#comments Sat, 10 Sep 2011 10:35:09 +0000 admin http://www.thearealist.com/area-formula/how-do-you-create-a-quadratic-equations-with-this-formula-arealength-x-width I’m doing a project on quadratic equations, and the question says, "Graph the length and area of each rectangle (length on the horizontal axis and area on the vertical axis)." I’m pretty sure that since this project is on quadratic equations, I have to graph a quadratic equation concerning the formula above, but I dont know how to create that quadratic equation :P Help!!

Well, my guess is that the length and the area will have a sort of quadratic relationship already, You are graphing, l vs. l*w

This is not really quadratic, because that, strictly, refers to equations where a single variable is raised to the power of 2 – were you graphing squares – area versus the length of a side, then you would have a clear quadratic.

So you really can’t do that – but my wife teaches high school, and she had trouble with kids just plain learning to graph – she would see a class that had issues and she would assign some stuff like this so that they could get more practice.

Microsoft Math allows you to construct graphs quickly and fold them into your documents easily.

]]> http://www.thearealist.com/area-formula/how-do-you-create-a-quadratic-equations-with-this-formula-arealength-x-width/feed 2 What can you conclude is the formula for the area of a circle of radius r? http://www.thearealist.com/area-formula/what-can-you-conclude-is-the-formula-for-the-area-of-a-circle-of-radius-r http://www.thearealist.com/area-formula/what-can-you-conclude-is-the-formula-for-the-area-of-a-circle-of-radius-r#comments Thu, 25 Aug 2011 14:11:52 +0000 admin http://www.thearealist.com/area-formula/what-can-you-conclude-is-the-formula-for-the-area-of-a-circle-of-radius-r Okay the premise is that a polygon is inscribed in a circle with radius r. As n increases, the shape of the n-gon gets closer and closer to the circumference of the circle. The limit becomes closer to one.

Now the question is: What can you conclude is the formula for the area of a circle of radius r?

Step-by-step explaination would be greatly appreciated. Thank you in advance!

This was detailed in this question:
http://answers.yahoo.com/question/index?qid=20100623000747AAjNUsa

But you’ll need L’Hospital’s rule from calculus to understand how to take the limit as n→∞

Hope this is helpful. (I saw no need to reinvent the wheel, so to speak.)

]]> http://www.thearealist.com/area-formula/what-can-you-conclude-is-the-formula-for-the-area-of-a-circle-of-radius-r/feed 3 What is the formula for the area of a regular nonogon when you know the sides and the apothem? http://www.thearealist.com/area-formula/what-is-the-formula-for-the-area-of-a-regular-nonogon-when-you-know-the-sides-and-the-apothem http://www.thearealist.com/area-formula/what-is-the-formula-for-the-area-of-a-regular-nonogon-when-you-know-the-sides-and-the-apothem#comments Tue, 23 Aug 2011 09:57:53 +0000 admin http://www.thearealist.com/area-formula/what-is-the-formula-for-the-area-of-a-regular-nonogon-when-you-know-the-sides-and-the-apothem What is the formula for area of a nonogon? I know the side lengths and the apothem.

Let me try….

The formula for area of a regular polygon is A = ½ (nR²sin(360°/n)). ¼(ns²cot(180°/n)) and nr²tan(180°/n) where…

n is the number of sides
R is the radius of circumcircle
s is the length of the side
r is the apothem

I can’t seem to find the area of a regular nonagon, but you can try using that formula I gave you.

Anyway… I hope this helps!

~Tsugara

]]> http://www.thearealist.com/area-formula/what-is-the-formula-for-the-area-of-a-regular-nonogon-when-you-know-the-sides-and-the-apothem/feed 2 Is 1/2 asn the area formula for regular pentagons? http://www.thearealist.com/area-formula/is-12-asn-the-area-formula-for-regular-pentagons http://www.thearealist.com/area-formula/is-12-asn-the-area-formula-for-regular-pentagons#comments Sun, 21 Aug 2011 02:09:56 +0000 admin http://www.thearealist.com/area-formula/is-12-asn-the-area-formula-for-regular-pentagons Is this the correct area formula for regular pentagons? If so, what do the "s" and "n" stand for. I will pick the first answerer to help me understand it.

Yes, it is correct, but a more common formula is:
A = (1/2)ap,

where a is the length of the apothem (the distance between the center to the midpoint of one of the side) and p is the perimeter. Since ns = p, where n is the number of sides and s is the length of each side, your formula is equivalent.

I hope this helps!

]]> http://www.thearealist.com/area-formula/is-12-asn-the-area-formula-for-regular-pentagons/feed 2 How to derive area formula for ellipse? http://www.thearealist.com/area-formula/how-to-derive-area-formula-for-ellipse http://www.thearealist.com/area-formula/how-to-derive-area-formula-for-ellipse#comments Thu, 18 Aug 2011 23:25:49 +0000 admin http://www.thearealist.com/area-formula/how-to-derive-area-formula-for-ellipse Ok i know it is abPI
An i also know the formula of ellipse is
(x^2/a^2)/(y^2/b^2)=1
And i use the integral of
2*PI * Y * sqrt(1+ G)
Where G is square of derivative of Y function of ellipse.
Sorry for maybe a little bit confusing explanation, but help is appreciated.
Thanks in advance.

… Total Area of Ellipse

= 4 { Area in First Quadrant }

= 4 { ∫ [0,a] y dx }

= 4 ∫ [0,a] (b/a) √(a² – x²) dx

= (4b/a) { [ (x/2)√(a² - x²) ] + (a²/2). [ sinֿ¹ (x/a) ] } … in [0,a]

= (4b/a) { [ 0 - 0 ] + (a²/2) [ ( sinֿ¹ 1 ) - ( sinֿ¹ 0 ) ] }

= (4b/a) { (a²/2) [ (π/2) - (0) ] }

= πab ……………………………………… Ans.
_________________________

Happy To Help !
_________________________

]]> http://www.thearealist.com/area-formula/how-to-derive-area-formula-for-ellipse/feed 1 What is the surface area formula for an octahedron? http://www.thearealist.com/area-formula/what-is-the-surface-area-formula-for-an-octahedron http://www.thearealist.com/area-formula/what-is-the-surface-area-formula-for-an-octahedron#comments Mon, 16 May 2011 20:50:05 +0000 admin http://www.thearealist.com/area-formula/what-is-the-surface-area-formula-for-an-octahedron To simplify this, couldn’t I just say that it is the area of one of the triangular faces X 8? I also need to know if this would work for a dodecahedron and an icosahedron. Thanks!!

Yes. For each of them, all faces are identical (if it’s regular, which it sounds like it is), so surface area is (area of one face) times (number of faces).

]]> http://www.thearealist.com/area-formula/what-is-the-surface-area-formula-for-an-octahedron/feed 106