Answer:
b=
Step-by-step explanation:
Considering the given figure the sides 'b' , '2' and '5' are making the sides of a right angled triangle in the top right corner of the square, where
Hypotenuse=5 , Perpendicular=b and Base=2
Using Pythagoras Theorem:

Implementing the values in the formula:


So, the value of 'b' is
which is same for the the given 'b' in the figure.