Question

Please solve this ASAP

Answer 1

A^2+B^2=C^2
4^2+b^2=6^2
16+b^2=36
-16        -16 
b^2=20
it would be 4.4 or if you want to round it 4. 

Answer 2

6^2 = 4^2 + b^2
36 = 16 + b^2
b^2 = 20
$b = 2 \sqrt{5}$