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**girlnamedfreak****Member**- Registered: 2006-11-12
- Posts: 7

how can i estimate the sine or tangent in a given triangle

and why is the sine of the 30 degrees equal to .5?

thanks

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

Your second question is answered about halfway down this page.

The first question is a bit more abstract. Could you elaborate a bit on what you mean, please?

Why did the vector cross the road?

It wanted to be normal.

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**girlnamedfreak****Member**- Registered: 2006-11-12
- Posts: 7

the exact question on my homework is: Estimate sinA and tanB in the given triangle ABC

then theres a picture of a right triangle thats labeled with A, B, and C and the 90 degree angle is shown

thats all it says and we never went over anything like this in class so I have no clue what to do

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**MathsIsFun****Administrator**- Registered: 2005-01-21
- Posts: 7,664

So maybe you could try to measure angle A (or B). If A is 30 degrees, then you can answer with sin 30 (=0.5), and tan 60 (=√3) (because if A is 30, B has to be 60).

If angle A is something else, maybe you could use your calculator

"The physicists defer only to mathematicians, and the mathematicians defer only to God ..." - Leon M. Lederman

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

Or, because it's a right-angled triangle, then a possible simpler way would be to measure the sides of the triangle and find their ratios.

A

|\

| \

| \ c

b | \

| \

| \

C ----------- B

a

Sin A in this case would be length a divided by length c, and tan B would be b divided by a.

That might change depending on which angle is the right angle though.

Why did the vector cross the road?

It wanted to be normal.

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