Question

plz solve this question..........

Answer 1

♦ Hello ★

°.° A , B and C are interior angle

.°. A + B + C = 180°

=> B + C = 180° - A

=> B + C/2 = 180° - A/2

=> B + C /2 = 90° - A/2

=> sin ( B + C/2 ) = sin ( 90° - A/2 )

=> sin ( B + C/2 ) = cos ( A/2 )

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