A similar topic, you will know yours when you understand it. In the triangle ABC, it is known that the internal angle A=π/3, the side BC=2, and the root number 3 is used to find the maximum value of the circumference Y?

Solution: According to the formula, a/sinA=b/sinB=c/sinC.

a=2√3，∠A=60

=>b = inch, c = inch (120 -B)

=> perimeter l=a+b+c

=2√3+4sinB+4sin( 120 -B)

= 2√3+4(sin b+√3/2 cosb+ 1/2 sinB)

=2√3+2(3sinB+√3cosB)

=2√3+2√3(√3sinB+cosB)

= 2√3+4√3(√3/2 sinb+ 1/2 cosb)

= 2√3+4√3 inches (B+30)

Because-1

1/2 & lt； sin(B+30)& lt； = 1 B = 60 at this time, that is, it is an equilateral triangle now.

=>l circumference =6√3