Respuesta :
A and B are complementary, that means m∠A+m∠B=90
Recall that sinA=cos(90-A), if sinA=8/9, cos(90-A) is also 8/9
therefore, cosB=cos(90-A)=sinA=8/9
Recall that sinA=cos(90-A), if sinA=8/9, cos(90-A) is also 8/9
therefore, cosB=cos(90-A)=sinA=8/9