I have a weird proof(?) that I can't figure out how to work.

It goes as follows:

Show that $\displaystyle \sin \theta=\cos\theta\tan\theta $

I also have a few true/false questions I wanted to make sure I have right:

1:$\displaystyle \sin\theta=\cos(90-\theta)$ my answer: False

2:$\displaystyle \tan\theta=-\cot(90-\theta)$ my answer: False

3:$\displaystyle \sin\theta=\frac{1}{\csc\theta}$ my answer: True

Many thanks for all of your help so far!