How do i solve this problem because i don’t understand

You are using a^2+b^2=c^2
since c is the hypotenuse

#1 the equation would be 16^2+b^2=34^2
16^2= 256
34^2= 1156
1156-256= 900
b^2=900 (now find square root of 900)
b= 30

You are now trying to find the hypotenuse or c in this so it is simpler

#2 equation - 4^2+2^2=c^2
16+4=c^2
20=c^2
c= 4.27