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**robin****Member**- Registered: 2005-09-23
- Posts: 3

Hi,

My kid brought some homework back and I sat down to help...... And got stuck *blush*

Well, his homework was easy, find the missing length or angle of a triangle etc. We finished that with no problems and I felt quite happy I seemed to of helped, but then he asked me about angles of a triangle -

Why are the angles always an exact figure, like 45 degrees or 61 degrees.

I should of just said, thats what the book says, but no, I went into explaining that the angles can have decimals and tried to explain about the Angle being built with Degrees and minutes / secs ... This sank in and then he said, -

What tangent should be used for a 32.47 degree angle ?

I grinned and opened the Trigonometric table page and found 32 degrees = 0.625

and 33 degrees = 0.649.. And said it lies within these too tangents.

But.... I couldn't explain what the exact tangent to use would be. I told him we'd revisit the problem and so here i am.... I've searched the net and havent found any such precise tangent tables or anything which will help me to understand and explain better the solution.

Sorry its a long one... Any help on this would be appreciated.

Robin

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**mathsyperson****Moderator**- Registered: 2005-06-22
- Posts: 4,900

A scientific calculator could tell you.

The calculator in the 'accessories' bit of your computer has a scientific mode, or you could use Microsoft Excel and put

=tan(radians([angle])), where [angle] is the angle that you want the tangent of in degrees. That would tell you the value to at least 10 decimal places, I should think.

Why did the vector cross the road?

It wanted to be normal.

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