# Math Help - trigonometry

1. ## trigonometry

2. Originally Posted by robasc

$\tan \theta = \frac{{\frac{1}
{2}\left( {d - y} \right)}}
{{x}}$

${\text{Use, }}\tan 3^\circ = \frac{{\frac{1}
{2}\left( {d - 3} \right)}}
{{18}}{\text{ to figure out }}d$

3. Well I came up with an answer of approximately 1.003cm

4. Originally Posted by robasc
Well I came up with an answer of approximately 1.003cm
No, the answer is 4.88668 cm $\approx 4.9$ cm, see here,

$18\times \tan 3^\circ = {\frac{1}
{2}\left( {d - 3} \right)}$

$2\times 18\times \tan 3^\circ =d-3$

d = 1.88668 +3
d = 4.88668 cm