# Math Help - Trig Question

1. ## Trig Question

Hi
I need some help on the following question:
In the triangle ABC to calculate the lengths of sides AB and BC.

P.S

2. Dear Paymemoney,

Consider Sin 27 and Tan 27 and relate them to the length that is given. If you need more help please don't hesitate to reply me.

3. ok this is what i have done, but it is incorrect.

$\frac{15}{sin90}=\frac{b}{sin27}$

$15sin27=bsin90$

$\frac{15sin27}{sin90}=b$

b=16.04
P.S

4. Originally Posted by Paymemoney
Hi
I need some help on the following question:
In the triangle ABC to calculate the lengths of sides AB and BC.

P.S
You should know that

$\sin{\theta} = \frac{\textrm{Opposite}}{\textrm{Hypotenuse}}$

and

$\tan{\theta} = \frac{\textrm{Opposite}}{\textrm{Adjacent}}$.

Label the sides of your triangle, substitute the values into your equations as appropriate, and solve for the unknown sides.

5. Dear Paymemoney,

The way you did is incorrect. I assume that you tried to use the Sine rule. But you have applied it incorrectly. In the first line you have written it should be 15/Sin27=BC/Sin90. But as "Prove It" had shown it could be done easily if you consider the Trignometric ratios of right traingles.

6. ok thanks i got the solutions.