It looks like it is -1 chief
I need you to post a diagram.
However, you are describing a 30 60 90 triangle and here is a good page to learn about those: http://www.1728.org/trig2.htm
You can use the ASA postulate which means angle side angle. if 2 angles and the including side are congruent to the corresponding parts of another triangle then the triangles are congruent. hope that helps :)
Answer:
28
Step-by-step explanation: