Question

Find AC. Round the answer to the nearest tenth.

A.
8.2
B.
8.9
C.
10.0
D.
28.9

Please help thank you :)
Need this within 30mins

Answer 1

Use the Cosine Rule:-

AC^2 = 6^2 + 8^2 - 2*6*8 cos 78
         =  80.04

So AC = sqrt 80.04 =  8.9 to nearest tenth