Respuesta :

Answer:

b=43.16

Step-by-step explanation:

You can use the Pythagorean Theorem so a^2+b^2=c^2

b^2+21^2=48^2

b^2 + 441 =2304

b^2 = 1863

b^2 = square root of 1863

b=43.1625

b=43.16