Respuesta :

<B be y

  • We know that complementary angles have sum 90°

[tex]\\ \sf\longmapsto y+21=90[/tex]

[tex]\\ \sf\longmapsto y=90-21[/tex]

[tex]\\ \sf\longmapsto y=69°[/tex]

<A=69°

Answer:

The measure of ∠B is 69°

Step-by-step explanation:

Given :

=> ∠A + ∠B = 90°

=> 21° + ∠B = 90°

=> ∠B = 90°- 21°

=> ∠B = 69°