Answer:
10.3
Step-by-step explanation:
We use the pythagorean theorem. (a^2+b^2=c^2)
3.9^2 + b^2 = 11^2
3.9^2 = 15.21
11^2 = 121
15.21 + b^2 = 121
Subtract 15.21 from both sides
b^2=105.79
Take the square root of both sides
b = 10.28
10.28 is closest to 10.3 and it is also rounded to 10.3, therefore 10.3 is the answer.
