Answer:
38.4
Explanation:
you start with the Pythagorean theorem, a squared + b squared = c squared.
you already have b- 10, and c- 22. So you substitute.
a squared + 10 squared = 22 squared.
a squared + 100 = 484
you subtract 100 from 484 and you have your answer.
484- 100 = 384
then you add a decimal before the 4
a= 38.4