Math Is Fun Forum

sk

Member

Registered: 2006-08-04

Posts: 19

hi dudes.. help me with this...

If in a triangle ABC a : b : c = 8 : 10 : 12 and the least angle is theeta, then  the greatest angle in terms of theeta is?

Last edited by sk (2010-08-02 19:38:40)

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: hi dudes.. help me with this...

Hi sk;

You can use the law of cosines to get angle gamma the biggest angle in your triangle.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

Bob

Administrator

Registered: 2010-06-20

Posts: 10,621

Re: hi dudes.. help me with this...

hi sk

Or the sine rule:

                              a/sinA = b/sinB = c/sinC

to write sinC in terms of sinA.

[note the shortest side will be opposite the smallest angle and the longest side opposite the largest angle]

[also you may asssume the sides are actually 8cm, 10cm and 12cm rather than just in that ratio, as the sine rule will work properly with triangles that are enlarged by a scale factor]

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