Find expert answers and community-driven knowledge on IDNLearn.com. Our platform provides prompt, accurate answers from experts ready to assist you with any question you may have.
Answer:
option 4
Step-by-step explanation:
the total interior angle of a triangle adds up to 180º. you're given it's a right triangle (90º) and the angle B, 21º. Add those up and you get 111º. 180º-111º=69º, angle C.