Question

If angle c=60° , b=5 ,a=4 then find the value of the c ?​

Answer 1

c=sqrt21

Explanation:

angle c is the angle between a and b, so use the cos law

c^2=a^2+b^2-2*a*b*cosC

c^2= 16+25-2*4*5*1/2

c^2=21

c=sqrt21