Question

pls help...need it urgently

Answer 1

$we \: know \: that \: \: a + b + c = 180 (given \: \: \: b = 90) \\ a + c = 180 - 90 = 90 \\ \sin( \frac{a + c}{2} ) = \sin( \frac{90}{2} ) = \sin(45) = \frac{1}{ \sqrt{2} }$

Please mark me as brainliest .