Simplify the following and write your answer in simplest form

1. 2. ∠b and ∠y are right angles. 3.? 4.? which two statements are missing in steps 3 and 4? ∠x ≅ ∠c △abc ~ △zyx by the sas similarity theorem. ∠b ≅ ∠y △abc ~ △zyx by the sas similarity theorem. = 2 △abc ~ △zyx by the sss similarity theorem. = 2 △abc ~ △zyx by the sss similarity theorem.

Tan198=asin164=? how to solve this? ?

What adds to be the bottom number but also multiplies to be the top number with 8 on the bottom and 15 on top