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**Maou-Sama****Member**- Registered: 2015-03-03
- Posts: 9

how to solve this please help.

*Last edited by Maou-Sama (2015-03-04 02:27:49)*

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**Bob****Administrator**- Registered: 2010-06-20
- Posts: 10,544

hi Maou-Sama

You can use trig on triangle OAC to get OA and AC. Leave your answers with root 3 when it comes up rather than an approximate decimal.

From that you can get the area of the triangle and the rectangle.

Then the sector by pi/3 times r squared / 2 and subtract.

Bob

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

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**Maou-Sama****Member**- Registered: 2015-03-03
- Posts: 9

thanks bob but when do you know which to pick

eg: cos30=√3/2 while tan 30=1/√3

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**Bob****Administrator**- Registered: 2010-06-20
- Posts: 10,544

Looks like you'll have to use cos and sin in this problem.

Bob

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

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**Relentless****Member**- Registered: 2015-12-15
- Posts: 631

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