two trig questions

girlnamedfreak · 2006-11-12 11:38:31

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

mathsyperson · 2006-11-12 12:48:52

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?

girlnamedfreak · 2006-11-12 14:56:24

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

MathsIsFun · 2006-11-12 16:42:22

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

mathsyperson · 2006-11-12 22:21:07

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.

Math Is Fun Forum

#1 2006-11-12 11:38:31

two trig questions

#2 2006-11-12 12:48:52

Re: two trig questions

#3 2006-11-12 14:56:24

Re: two trig questions

#4 2006-11-12 16:42:22

Re: two trig questions

#5 2006-11-12 22:21:07

Re: two trig questions

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