Cosine rule question

If I have been given a=1, b=2 and angle C =30 degrees. As I have been given the included angle I used the cosine rule but I got 1.54 but answer is 1.239... have I entered it wrong in my calculator perhaps? I used c= a^2 + b^2 - 2ab cos C

Reply 1

MarkFromWales

10

Original post by Helloaaa

If I have been given a=1, b=2 and angle C =30 degrees. As I have been given the included angle I used the cosine rule but I got 1.54 but answer is 1.239... have I entered it wrong in my calculator perhaps? I used c= a^2 + b^2 - 2ab cos C