Respuesta :
Answer:
nice and
since it is complementary then a +b = 90
and substitution gives
69 + b = 90
b = 21
hope this helped and brainliest pls
Answer:
21
Step-by-step explanation:
I assume you are dealing with complementary angles.
m<a + m<b = 90
69 + m<b = 90
m<b = 90 - 69
m<b = 21