I need help on number 6 and 7

Answer:
1. c=13
2. a=12
Step-by-step explanation:
We have to use the Pythagorean theorm
a^2+b^2=c^2
(5*5)+(12*12)=c^2
25+144=c^2
169=c^2
Now we have to square root 169 to find c
[tex]\sqrt{169}[/tex]
c=13
For this one we have to do c^2-b^2=A^2
(15*15)-(9*9)
225-81=a^2
144=a^2
[tex]\sqrt{144}[/tex]
a=12