i duno how to do~ :(

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- Jun 23rd 2006, 06:54 AMxiaozhelp mi wif tis questions
i duno how to do~ :(

- Jun 23rd 2006, 07:11 AMQuickQuote:

Originally Posted by**xiaoz**

so substitute 8 for n

and solve

number 2 asks you to solve for n, so lets do it...

use the distributive property

simplify

multiply both sides by n

subtract 180n from both sides

subtract

divide both sides by A-180

simplify

simplify

and thats what n equals. Substitute the given number for A (157.5)

and solve, this will give you the answer for a.ii - Jun 23rd 2006, 07:29 AMxiaoz
how to do a(iii) ?

- Jun 23rd 2006, 08:16 AMSoroban
Hello, xiaoz!

Quote:

i duno how to do~

a) The measurement of an interior angle of a regular polygon of sides

. . . is given by the formula: .******

(1) Find the measure of an interior angle of a regular polygon with 8 sides.

How about plugging in ?

Quote:

(2) Write in terms of .Hence, find the number of sides

of the regular polygon with interior angles measuring 157.5° each.

We have: .

Multiply both sides by

Then: .

Factor: .

We are told that

Plug it in and determine

Quote:

(3) Find the regular polygon such that when the number of sides is doubled

the measure of an interior angle is doubled.

This is the only one that's tricky . . .

For sides, the angle is: .**[1]**

For sides, the angle is: .**[2]**

Equate**[1]**and**[2]**: .

. . which simplifies to: .

. . which factors: .

. . and has the positive root: .

This checks out.

With we have an equilateral triangle: interior angle

Double the number sides and we have a hexagon: interior angle

. . . . . . . . ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

******

This is a really**stupid**way of writing the formula!

The proper form is: .

It can be shown that the sum of interior angles of any n-gon is:

If all angles are equal, each angle measures: . degrees.

Someone is going to say, "What's the difference? .They're equal!"

Well, that is certainly true.

This means that we will have*dozens*of formulas to memorize . . .

. . .

Catch my drift?

- Jun 23rd 2006, 10:51 AMCaptainBlackI have split this thread
Xiaoz,

I have split this thread so that your new question is in a thread

of its own.

It is a good idea to create a new thread when you have a new

question, otherwise your thread may become messy and difficult to

follow.

RonL - Jun 24th 2006, 04:19 AMxiaoz
ok..