Find the 15th term of the geometric sequence 2,6,18

Which statement is true? the given sides and angles cannot be used to show similarity by either the sss or sas similarity theorems. the given sides and angles can be used to show similarity by the sss similarity theorem only. the given sides and angles can be used to show similarity by the sas similarity theorem only. the given sides and angles can be used to show similarity by both the sss and sas similarity theorems.

How many sides does a regular polygon have if each exterior angle measure is 45 degrees explain your answer, i really don't understand this.

Tan198=asin164=? how to solve this? ?