Math Is Fun Forum

Estela

Member

Registered: 2011-07-21

Posts: 1

Geometry

I need help with some problems, im taking geometry online, and its so hard! i dont get the problems and all, can you help me with this one please Find the area of the smaller segment whose chord is 8" long in a circle with an 8" radius. Thank you, and if you can explain it to me, I'll be more than happy

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: Geometry

hi Estela

welcome to the forum.

Just to check-is the solution 32"?

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“Here lies the reader who will never open this book. He is forever dead.
“Taking a new step, uttering a new word, is what people fear most.” ― Fyodor Dostoyevsky, Crime and Punishment
The knowledge of some things as a function of age is a delta function.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,623

Re: Geometry

hi Estela,

Have a look a my diagram below.

The radii BA and BC are both 8 and so is AC. 

So the triangle ABC is equilateral which means that angle ABC is 60 degrees.

The segment is the red bit.

So I'll do this like so:

Calculate the area of the sector of the circle (red plus yellow/red bit).

Calculate the area of the triangle (yellow/red bit)

Subtract to get the red area on its own.

Calculate these, subtract and you'll get the area.

I made it

Post back if you need more details

Bob

Last edited by Bob (2011-07-21 06:14:39)

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob

soroban

Member

Registered: 2007-03-09

Posts: 452

Re: Geometry

            ..*.*.*..
         .*:::::::::::*.
      A * - - - - - - - * B
       *  *     8     *  *
          8 *       * 8
      *       *60°*       *
      * - - - - * - - - - *
                O

Edit: Ah, Bob beat me to it . . . *sigh*
.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,623

Re: Geometry

hi soroban,

bobbym does that to me all the time so don't worry.  Two heads are better than one.

You might like this:

http://www.geogebra.org/cms/

It'll knock minutes off your post back times!

Bob

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Children are not defined by school ...........The Fonz
You cannot teach a man anything;  you can only help him find it within himself..........Galileo Galilei
Sometimes I deliberately make mistakes, just to test you!  …………….Bob