My Math Forum Height unknown but need area.

 Algebra Pre-Algebra and Basic Algebra Math Forum

March 24th, 2014, 10:51 AM   #11
Senior Member

Joined: Nov 2013

Posts: 247
Thanks: 2

Re: Height unknown but need area.

Quote:
 Originally Posted by eddybob123 You can use Brahmagupta's Formula for cyclic quadrilaterals, which can be generalized for any non-cyclic quadrilateral.
That will work for any quadrilateral. Even concave? And I am talking about:
$A= \sqrt{(s-a)(s-b)(s-c)(s-d) - 1/4(ac+bd+pq)(ac+bd-pq)}$

and the other one that I had will work for quadrilaterals internally tangent to a circle such as squares, rectangles, and isoscoles trapezoids but not the ones you can't inscribe in a circle with each vertex meeting a point on it or 1 point being outside the circle. That is this:
$A= \sqrt{(s-a)(s-b)(s-c)(s-d)}$

For example a 5 * 5 square

$A= \sqrt{(10-5)(10-5)(10-5)(10-5)}$
$A= \sqrt{5^4}$(is this right)
$A= 5 * \sqrt{25}$
$A= 25$

And I would get the same thing with this:
$A= 5^2$

March 24th, 2014, 12:07 PM   #12
Newbie

Joined: Mar 2014

Posts: 10
Thanks: 0

Re: Height unknown but need area.

Quote:
 Originally Posted by Denis Fiverr.com/Cheezees http://www.fiverr.com/cheezees/do-up-to ... -questions And you only charge 5 bucks?
Yip, just 8 questions (1a, 1b, 1c, etc. are all considered separate questions). I just love doing math!

~Cheezees
Fiverr.com/Cheezees

March 24th, 2014, 01:18 PM   #13
Senior Member

Joined: Sep 2012

Posts: 764
Thanks: 53

Re: Height unknown but need area.

Quote:
 Originally Posted by caters ...but not the ones you can't inscribe in a circle with each vertex meeting a point on it or 1 point being outside the circle...

March 24th, 2014, 01:25 PM   #14
Math Team

Joined: Oct 2011

Posts: 14,597
Thanks: 1038

Re: Height unknown but need area.

Quote:
Originally Posted by Cheezees
Quote:
 Originally Posted by Denis Fiverr.com/Cheezees http://www.fiverr.com/cheezees/do-up-to ... -questions And you only charge 5 bucks?
Yip, just 8 questions (1a, 1b, 1c, etc. are all considered separate questions). I just love doing math!
~Cheezees
Fiverr.com/Cheezees
So, if a poor atudent has 5 bucks a week allowance, you'll take it?

March 24th, 2014, 01:37 PM   #15
Newbie

Joined: Mar 2014

Posts: 10
Thanks: 0

Re: Height unknown but need area.

Quote:
Originally Posted by Denis
Quote:
Originally Posted by Cheezees
Quote:
 Originally Posted by Denis Fiverr.com/Cheezees http://www.fiverr.com/cheezees/do-up-to ... -questions And you only charge 5 bucks?
Yip, just 8 questions (1a, 1b, 1c, etc. are all considered separate questions). I just love doing math!
~Cheezees
Fiverr.com/Cheezees
So, if a poor atudent has 5 bucks a week allowance, you'll take it?
If you need step-by-step help understanding concepts through examples, yes. That or 60USD for tutoring (my average rate). Why do you ask?

March 24th, 2014, 04:32 PM   #16
Senior Member

Joined: Nov 2013

Posts: 247
Thanks: 2

Re: Height unknown but need area.

Quote:
Originally Posted by eddybob123
Quote:
 Originally Posted by caters ...but not the ones you can't inscribe in a circle with each vertex meeting a point on it or 1 point being outside the circle...
I know it is. Some non-cyclic ones are tangential meaning they are externally tangent to a circle but some aren't

March 25th, 2014, 02:48 AM   #17
Math Team

Joined: Oct 2011

Posts: 14,597
Thanks: 1038

Re: Height unknown but need area.

Quote:
 Originally Posted by Cheezees Why do you ask?
Because I hope the moderator(s) kick you out for spamming

March 25th, 2014, 06:30 AM   #18
Newbie

Joined: Mar 2014

Posts: 10
Thanks: 0

Re: Height unknown but need area.

Quote:
Originally Posted by Denis
Quote:
 Originally Posted by Cheezees Why do you ask?
Because I hope the moderator(s) kick you out for spamming

March 25th, 2014, 08:54 AM   #19
Math Team

Joined: Oct 2011

Posts: 14,597
Thanks: 1038

Re: Height unknown but need area.

Quote:
 Originally Posted by Cheezees Yet YOU keep bringing it up and I answer questions on the forum for free.
I bring it up because you post the url to your site now and then.
I'm trying to follow this rule:
viewtopic.php?f=42&t=35190

 March 30th, 2014, 09:21 AM #20 Senior Member   Joined: Nov 2013 Posts: 247 Thanks: 2 Okay so why is a parallelogram a special case of a trapezoid? As far as I know trapezoids have 1 pair of parallel sides while parallelograms have 2. I understand why the 3 sides equal trapezoid is a special case of the isosceles trapezoid and that is because the word isosceles means at least 2 sides are equal, meaning that anything equilateral is isosceles. What I don't understand is how the 2 pairs of parallel sides on a parallelogram makes it a special case of the trapezoid in general.

 Tags area, height, unknown

### I am off parallelogram, rhombus, a rectangle and a trapezium who am I

Click on a term to search for related topics.
 Thread Tools Display Modes Linear Mode

 Similar Threads Thread Thread Starter Forum Replies Last Post zxcvbnm123 Number Theory 1 February 19th, 2014 01:26 AM giorgal2 Algebra 4 October 13th, 2012 05:14 AM fishinmyi Algebra 6 October 27th, 2011 09:34 AM jsmith613 Calculus 7 November 15th, 2010 01:57 AM hahaha Algebra 7 November 12th, 2007 09:38 AM

 Contact - Home - Forums - Cryptocurrency Forum - Top