1. ## find an angle

Hi! I have a trig problem.

What we know:
AB = 12 mm
CD = 6 mm
DA = 20 mm
ABC = 110°
BCD = 130°

What I would like to know:
DAB = ? °

Thanks a lot in advance for any help!

Regards

2. ## Re: find an angle

angle DAB $\approx 50.48{}^{\circ}$

3. ## Re: find an angle

Thanks but did you determinate it algebraically? How?

4. ## Re: find an angle

Law of sines in triangle ABE and again in triangle DCE

$\frac{\sin E}{6}=\frac{\sin 50^{\circ }}{d}$

$\frac{\sin E}{12}=\frac{\sin 110^{\circ }}{d+20}$

where d = ED