Question

In a $\Delta$ ABC , 2s = perimeter and R = circumradius. Then,S/Ris equal to

• A. sin A + sin B + sin C
• B. cos A + cos B + cos C
• C. sin A/2 + sin B/2 sin C/2
• D. None of these

Answer 1

The correct option is A

sin A + sin B + sin C

$\frac{s}{R}=\frac{(a+b+c)}{2R}=\frac{a}{2R}+\frac{b}{2R}+\frac{c}{2R}=sinA+sinB+sinC$