Use the pythagorean theorem to find b.

b=5

Step-by-step explanation:

pythagorean theorem:

 where c is the hypotenuse.

In this case, we know a and c, so we have to solve for b:

To answer this question you must use Pythagorean theorem

a and b are the legs (the sides that form a perpendicular/right angle)

c is the hypotenuse (the side opposite the right angle)

In this case...

a = 12

b = unknown

c = 13

^^^Plug these numbers into the theorem

solve for b

+ 144 = 169

= 25

To remove the square from b take the square root of both sides to get you...

b = 5

Hope this helped!

~Just a girl in love with Shawn Mendes