Idon't know how to do this
we are using sine, cos, tangent.

Okay well you have a 90 and 73 degree angle. 90+73 is 163. All triangles have an interior of 180 so you subtract 189-163 to get the top angle, which is 17. Then you have to figure out one of the other sides. After that you would use pythag Theorem to find out the last side by doing a^2+b^2=c^2. In this case 6 would be c squared because c is always the hypotenuse, or the side across form the 90 degree angle. Then from there you can use SOHCAHTOA. sin is opposite / hyp. Cos is adjacent / hyp and tan is opposite/ adjacent.