Answer:
or approximately 16.09
Step-by-step explanation:
Using the pythagorean theorem, the formula would be 
insert 15 into a and 22 into c.
you will get 
That simplifies into 225 +
= 484
subtract the 225 from 484 to isolate the variable
then you will get
= 259
square root both sides to get rid of the square:
=
if you want the decimal version, fully square root the number and you will get approximately 16.09 (rounded to the nearest hundredth)