If I am give the the sides of a triangle, where

Question

Side RA=4
Side AB=4.8
Side RB=7.1

How do I find Angle RAB?

Thanks!

Answer 1

Law of Cosines

C^2=a^2+b^2-2abCosC

so label your sides a, b, c

you want angle c to equal RAB
so RB=C
RA=a
AB=b