hscishard
Active Member
AM I CRAZY???????
this question does not work!
Q3ai
Triangle ABC has sides AB=3cm, BC=6cm and CA=5cm.
Use the cosine rule to show that Angle BAC = 94 degrees.
I keep getting a negative answer - HELP!
I hate people that can only use calculators, AND can't use them properly.the cosine rule is getting me a negative answer!!!
and i need "sinC" before i can do area of triangle!!!
(9+25 -36)/ (2x5x3)
=-1/15
Shift cos, angle is approx 93.82