Answer:
[tex]\sqrt{21}[/tex]
Step-by-step explanation:
Use the pythagorean theoreom, a^2+b^2=c^2.
We know the hypontenuse and one of the sdes
a^2+2^2=5^2
a^2+4=25
subract four from both sides to isolate variable
a^2=21
square root both sides and you have the answer of sq root 21!
Edit: the answer for your next question is the last one b/c it satisfies the Pythagorean Theorem
