19^2 + x^2 = 21^2
19^2 = 361
21^2= 441
361 + x^2 = 441
x^2 = 441-361 = 80
x = sqrt(80) = 8.944 round to nearest tenth = 8.9
Answer:
ADB and DBC
Step-by-step explanation:
Angles ADB and DBC are both marked with three curved lines which shows that their angles are congruent to each other.
Hope this helps! :)
